Hi,
I'm a little confused ( it's probably my age) but you say you got him only 12 days ago but he hasn't eaten for 5 weeks?
How/ what was the previous owner feeding him? Snakes are creatures of habit and any change can put them off eating for a time. I think he looks in the second picture as though he may be about to pass a dookie but a full picture of the snake might help us judge his condition better.
I'm curious why the breeder would let him go as a non-eater - was he going into shed?
del