Replacement Hogan iron pins

Anybody know what type of metal the original Hogan pins were? I understand that with modern epoxy, they are probably not necessary, but since I am going to be getting a press to remove them, I may as well put some back in. Looks better and will never have to worry about heads flying off.
I don’t want them to rust, so I have been thinking of using stainless. I’m not a machinist or metallurgist so I thought I would ask before I finalize the plan. thx