Jinxxy seems to be where everyone's moving, though itch.io might also be an option!

picarto has made a store specifically due to gumroad going to crap. not sure of the details, but worth a look.

Itch.io is always a good choice. I've seen a lot of people selling models over there

Fiverr might also work, though I think they are geared more to individual manufacture than to selling a standardized item.
I even saw people using ebay!
But overall I think itch.io , as suggested by Gelemar and SomeWAN, would be the place to go for the moment.

Did you check in how far you could use the "commission" option here in FA to offer your standardized models?