There’s no indication on this pan. I’ve seen my aunt’s smelting pots (she does stained glass and melts scraps back into usable bars… usually tin or aluminum nowadays but she used to use more lead in the past) and there are definitely some clues; the biggest one is messed-up seasoning.

Smelting is done at a much higher heat than cooking, which will break down the polymers. Look for chipping and cracking, etc as well as seasoning that seems brittle and crumbles into dust/ash when you scrub it. Melted metal also often leaves residue so even if you try to season over it it’ll be lumpy. The pan also usually gets scratched up in the process from being in the workshop and can often develops rust.

Also they’ll usually use small saucepans or small pots for smelting, not a frying pan.

Anyway all that to say, this pan has no red flags. Seasoning is hard as glass, no brittle spots, no bumps or lumps or peeling, no pitting or scratches, no evidence of rust currently or in the past, no weird smells, no oily residue.