Hmm, this is interesting. I did not realize that such models existed, especially from these two manufacturers.
Tanaka Springfield 1873 seems to be a dummy modelgun. It is made of metal and wood, with SMG marking and manufacturer name shown prominently on top of chamber.
Marushin rifle 1891 is another dummy modelgun, with 133cm and 102cm length variants. It is much simpler design, but also seems made of metal and wood. No SMG marking, only manufacturer name.
Do you know anything more about these models?
(all three are currently on sale on YJA)