The Classic 350 reborn has the 500 fenders & rear fender support bars.
Differences between them on the 350 "J Bullet" I can see are:
Casquette nacelle ring, rear fender, rear fender support bars, tail light, air box, exhaust silencer, seat, tank.
Cosmetic changes, basically "badge engineering", same stuff RE has been doing for a long time. No info on rear wheel size. We'll have to wait for a road test to see if there are kinesthetic differences. It definitely has the Olds Skool 350 Bullet vibe down pat though.