Is he rubbing on things or clamping his fins at all? I've heard one way to tell if it's velvet is to take a flash picture in a dark room. Supposedly the flash lights it up perfectly. It's hard to tell but offhand, he doesn't look like he has velvet. If you want to be on the safe side, put him in 3 tsps of AQ salt per gallon and get the heat up to about 86 degrees (slowly so as not to shock him).
With velvet, even if you can't necessarily see the gold coloring, you can usually see an uneven texture on the scales because of the protozoa.
If you're pretty sure based on what I've said that he doesn't have velvet, then still keep him in 1 tsp of AQ salt per gallon for a week. I can't tell for sure if that's fin rot but even if it isn't, the AQ salt will help prevent any fin tears from becoming infected.
Hope this helps. Good luck, Creat. It was good of you to rescue him.