Just as before the sun is in Aquarius, and the only place making sense for the moon is Pisces. The moon was in Pisces on two days in 1960: the 30th and 31st of January. On both dates Saturn was in conjunction with Mars.

On the 30th there were three aspects The moon with Saturn, the Moon with Mars, and the Sun with Neptune. None of these yielded any startlingly "Gabriel" type qualities.
On the 31st there was an additional conjunction of the Sun with Mercury. I could take or leave this, but the interesting part is the two aspects, the Moon with Jupiter and the Sun with Uranus. The aspect of the Sun with Uranus sounded especially like Gabe, and so I now believe that if Gabe was born in 1960 it was on January 31st!

Here is Gabriel Knight's horoscope based on this date:

With the Sun in Aquarius and the Moon in Pisces.

You are intuitive, something of a mystic, leaning on your hunches and your inspirations and capable of going far, either toward truth or toward fallacies through the following of your swift mental processes.

You have a feeling for poetry that makes it appear a science, and for science that makes of it a sort of poetry. Your combination of the real and the abstract, the imaginative and the demonstrable, the mystical and the earthly, gives you a broad hold on all branches of human knowledge and thought.

You need a good education, strict discipline in logic, and the development of a respect for accuracy and fact. Without this intellectual training you can become a first-class visionary, spiritualist, medium or clairvoyant, believing in ghosts, fairies, and hobgoblins. In any case you will be fascinated throughout life by the unseen, the mysterious, and the unusual, which may give you strange fears and phobias and cause you to be gullible on some points at the same time that you are completely rational on others.

You lead a private life of your own, into which few other people ever penetrate. You may have delusions either of grandeur or persecution, genius, a belief in witches and warlocks, a propensity to believe in alchemy, or that there will befall woe if a black cat crosses your path.

There is an odd admixture of the irrational with all the otherwise completely sane things that you do and believe but so great is your grip on reality that these oddities rarely amount to anything and really lend color and mystery to your personality. In your emotional life you are idealistic, loyal, sensitive, and easily imposed upon and will be hurt rather than angry at being fooled ."

The aspect of the Sun and Uranus:

"You've sown your wild oats - and how! Your intellectual development was a good deal in advance of your emotional development , and as a result you had ideas, notions, theories, of independence and of human relations which you put into practice, considerably to the despair of your elders. You're a liberal in every way, with advanced social, political, and personal ideas. Individualism is very important to you and your own ego comes first. As you grow older this outlook broadens from the purely personal to the more general, you turn from egocentric to humanitarian, interested in large ideas, large groups of people, social problems in the large.

This is one of the aspects of idealism but on its way to that state it foes through many ramifications. You have been dejected and depressed and discourage, probably you've had your share of unconventional and erratic love affairs. You always tend to be something of a romantic, no matter how much you control, or how much you learn to translate the personal into the impersonal, an adventurous spirit keeps gnawing at you. This is the aspect of Ulysses, forever wandering the seas - even when he's sitting by his hearth with Penelope. This adventurous urge, leashed and controlled and directed by a sound mind, will produce works of art, for the creative urge is powerful, with a touch of inspirationalism. Translate your adventuresomeness to intellectual, rather than personal variety, and theworld is at your feet.

Occultism is interesting to you but with a powerful mentality, dangerous.

You have a periodically explosive temper and must learn the lessons of cooperationboth with the world in general and with individuals. You tend to think that you are right and all the rest of the world is crazy, which doesn't really impress the world."

The Aspect of the Moon and Jupiter:

"You are optimistic with respect to financial matters You have a feeling that the purse will always be full, and the extravagance resulting therefrom may become dangerous to your security.You are sunny and open-hearted, tolerant of other people and of yourself as well, a kind of happy-go-lucky individual, taking people as you find them, and consequently popular. You usually have some share of the world's goods, though this doesn't in itself make for security - money comes and goes without causing you much worry, but it does not get saved very consistently."

Sun in Conjuction with Mercury

"You have a sound mentality. Along whatever lines you work you are fundamentally same. You have anassurance against serious or permanent mental difficulties which will carry them through a great deal of stress and bring them out the right side.

You have fixed opinions though. You don't understand the other fellow's viewpoint too well, and you aren't interested in talking his language.You are studious and sound in your intellectual work, but this position does not in itself make for creative ability. This will make for perseverance - the ability to add effort and resolve."

Saturn in Conjuction with Mars

"You will have to watch out for a tendency to be too accommodating and obliging. Your good-nature will either get you into trouble or cause you to be imposed on. You are so aware of social matters that you know how to please people and you are inclined to be, if possible, too self-sacrificing and self-effacing. This, in a selfish world, is a charming quality, but if carried too far it can nullify your individuality and you abilities. You are sure of yourself. You don't efface yourself through timidity but rather through being so sure that you don't feel the need to argue about it.If you can learn to translate this assurance into action and expression your calm and balanced nature will carry you far. Since there are squares to your Sun andMoon, you'll learn to do this without any trouble.

An artistic or professional career is your best medium. Medicine, the law, and especially the ministry may appeal to you, from the idealistic, sacrificial, and service viewpoint, for this is the aspect of the soul dedicated to an ideal. Your mental qualities are excellent, inclining on the creative sideto be imitative in the beginning and then strikingly original. Because of the Sun square Uranus you have plenty of energy and ability, because of the conjunction of The Sun and Mercury, luck in financial matters and business deals.