I haven't been collecting 22 rimfires as much as accumulating them. none of the ones I have do not have plastic or mystery metal in them.
BSA single shot model 12/15
BSA single shot model 15 with Canadian acceptance markings
Model 52B Winchester made in 1946
H&R model 12 single shot with U.S. on the receiver
Marlin model 25
Thats about the extent of my 22 stable. Frank