They appear to be stainless New Model Blackhawk hammers. If so, they should fit any of the New Model (NM) revolvers based on the NM Blackhawk design: Vaqueros and New Vaqueros, mid-sized frame flat-top NM Blackhawks, as well as the NM Super Blackhawks.
I have a couple of these laying around too, as I changed them out for the wide spur Super Blackhawk style on my 357 and 45 caliber Blackhawks to match my 44 Super Blackhawk. It was a 'drop in' conversion.