Kudos to giving him a good home! Hope you can get him eating in no time.
Some suggestions:
Until he's an established eater (ie feeding regularly) I would not handle him. This is most likely stressing him out and most of the time a stressed out snake = a non feeder.
Also, what was he eating before you got him? Jumbos may be right for his size but if he's being a picky eater I'd offer a smaller prey item - that might jumpstart his feeding responses.
And, idk if you're taking him for walks in public/around your neighborhood or whatnot but just be weary of people who don't like or are scared of snakes. They may not appreciate an adult boa be out in public around them/in their view (even if it's in your front or back yard or the like).
For pics: I add mine to photobucket and copy and paste the image code into a message.