Well I have a friend that is 25 and looks way older than Gassiev , it's all genetic. The thing with Gassiev is that he has beard.
Some people age better than others, I have relatives who's faces are covered with wrinkles at 42, and people in my family who look like they're 25 years and they're in their mid 30's. He's probably telling the truth, its just more anti-Wilder crackpots looking for reasons to discredit his biggest win, or paint him as an even bigger bum if he loses.
Wilder is nearly 33 but based on his speech /tweets/dress sense/general actions you would think he was 8.
He is the age he says he is why all the controversy nonsense over this there is absolutely no proof that he is older than what he said he is ?
He is a bit older than stated (he said in an interview he watched Ali fight for the world title when growing up - do the maths, and numerous people have stated that he's 40 at least). But I don't say this to discredit Wilder, if Wilder wins I'll give him full credit as Ortiz is a top 5 HW and about, if not the best available opponent.
Cuban defector. You know that 38 isn't his real age. They can't defect, and tell the promoters they are already 40 years of age, because no one would touch them.