I'm posting this working on the assumption that you may not be familiar with iguanas and their diet needs etc. Just trying to help
Glad you rescued this poor iguana. From the looks of his coloring he was definatly not getting the right diet [high calcium is
very important] but he appears from the photos to be alert and his eyes look bright which is good! Taz, my 11 year old, 6 foot long iguana, is fed only collard greens, dandelion greens, turnip greens and mustard greens. I will give him some ocassional carrot shreds, banana or diced orange mixed into those. An iguana's lighting is extremely important also -basking bulb from above for heat to digest food,[no heat rocks!
NEVER use heat rocks for iguanas] and a UV bulb [I use zoo med repti-sun] -through wire, not glass as glass filters out the vitamins they need.
The flaky skin you described on his face probably just means he is shedding and thats a good thing, it will happen every so often and is normal, but its important to keep him misted to help aid the skin in coming off -don't peel it off if you feel any resistance in it or you will hurt him, but if its loose and peels easily [like sunburn] then its okay to help off.
Iguana's tails will break off if someone grabs them by the tail. Sometimes they will grow back, but they are never the same. Oh yes -the lighting, he should have at least 8 hours of darkness a day, that is important in their health also. So if he is in a busy area, try to give him his quiet and at least semi darkness time at night.
I think its great that you rescued him and its nice that you have put him in an area where he will get attention and see people -they love attention and will even learn their name. They are very intelligent creatures, and make quite a unique pet when cared for properly and will live to be about 15 years old.
Diet note: If you can't find the greens listed above,[most Redners and WalMart carry them thoug] L&M pet products [available at Pet Supplies Plus in Shillington] makes a calcium powder which can be sprinkled on his food as a supplement. Avoid -lettuce, kale and spinach in his diet as they are anti-oxidents and will deplete the calcium he needs. The lettuce is just very low in all nutrition for an iguana so he'd starve if thats all he was fed.
I wish you luck with him -enjoy, you are a great person for rescuing him.
Edit:You mentioned getting his food when you got him at the yard sale - canned\bottled\pre processed type iguana food, is really not a good source [alone] of nutrition for these animals -they need fresh greens because they are vegetarian and that is what they live on in the wild.