Crosshair, I have a lead mold for making hammer heads, I have another hammer that uses round wood disc, another that uses leather rolls of material, I use and collect hammers, the hammer that is used around mills and lathes is called a palm hammer-no handle and is used to bump and secure work being held. I do not know of a commercial model but all a machinist has to do is see one used to understand how helpful they are. The lead weight adds weight to the swing and does not mar, I discourage lead casting with kitchen type equipment like muffin pans, but, the tin muffin pan is near the perfect size.
Lead and tin: When determining lead hardness to a small degree I drop the ingets, lead hits the floor with a dead sound, no bounce, lead with a hith tin content has a ring sound something like metal.
F. Guffey