I also adopted a 3 yr old male last year. In maybe July i think. He was under sized 565grams. And kept in horrible conditions. No heat pad of any sort, no hide, no humidity, cage looked like it hadnt been cleaned in a year or more. He is now up to 1000grams and seems very healthy. He is still shy but healthy. He whistles when he sheds other than that no problems. It took about 6 sheds before he finally lost all the eye caps he had. And he seems to see fine now.

From what i have gathered from this expierence is that they are very resilient snakes and given a chance can usually make a healthy recovery. Also he is a eating machine as a result of being starve for so long. At least that is what i think. He has never refused food.