its overbuilt and underbuilt.
the 5/8 base plate really doesnt serve any purpose except for weight. The welds from the baseplate to uprights are pretty dinky for that size material and the way you have the winch setup, you should have at least 1 gusset, i not two per side, otherwise your just going to bend it, even bend the whole thing over. You could have built that whole thing out of 1/4" with proper gussets and stiffners, and save at least 30lbs.
using 1/4" angle(2x2?) will not hold up to the winches' full potential.
Probably a buzz kill, but IMO you should have posted before painted because there are some major strength issues you overlooked.