Raditto, it may be that the woman had so many kitties that he didn’t get a lot of socialization with people. When there are lots of other kitties around, he may have learned how to interact with other kitties much, much better than with people.
Please, please be patient. He is probably a bit scared and anxious about his new situation. If you try to force him to come out, it will not help the relationship of trust you’re trying to build with him. He needs to not be scared of you, on top of being anxious about his new home and the fact that there aren’t ANY other kitties there.
You may find that getting a friendly, socialized kitty will help teach him that people can be trusted. If that’s not an option, I recommend plain (unsweetened) fingertips dipped in yogurt, offered while you’re sitting still, all the way down on the floor, within sight. Do not *force* him to come out, though, and try not to stare at him; that can be very scary to a frightened cat.
A Cat Dancer toy is inexpensive, and may help draw him out from his hiding place. When he comes out, make a happy, not-loud noise, and avoid sudden moves. Sudden moves and loud noises will probably scare him further.
He sounds lovely, just a bit unsure of his new surroundings and people. Try to keep a daily routine that’s pretty predictable. Try not to stare, or make loud noises or sudden moves. When he does something you like, be sure to make a happy, quiet noise, and if he’s in reach, slowly reach over to pet him.
(Another kitty would probably be a good idea for him, at some point. He’s very used to being around other cats.)