I always see his age-look, physique, and hair as Larry Davidish for some reason. The main thing is, unless he's intentionally altered his appearance, he ought to look like Andy Kaufman. I mean, you know when you see someone you know, you know. Your friend from kindergarden can walk past your perifery and you know it's them. Fatter, skinnier, balder, it doesn't matter, you just know.
I picture him growing a beard and long hair. Not being fat. Or maybe looking like the back of the man ont the VIP page. Tall, short brown hair and only 20 years older.
Also Kaufman was a health nut took his vitamins ate good (Except Ice-Cream). I think he would look very well for his age.