Just picked up a 1985 marlin 39a golden missing the hammer extension mine does not have the cross bolt safety. Looking for the flat one anybody have one they would like to sell.
Dunno whether a whole lot of GS would have the flat ones that Marlin and Williams used to make. Also Marlin changed hammer designs a couple of times and you'd almost have to have the rifle with you when you found an extension. Note the difference of the hammer profile in the bottom two units.