A customer brought in one of the German revolvers along with a tin of the "gas" shells. I couldn't read much of the German on the tin - except for ACTUNG! Anyway, we fired on of the gas shells and boy didn't that crap sting your eyes - even pointed well away - it just seemed to permeate the air. Probably CS powder.
As to starter/training pistols - as a starter it has to be able to fire at least three shots -one for go and two rapid pops to signal a mistart and call the runners back to the starting line. Training guns were used to condition dogs and horses to gunfire - starting with realitively mild reports and moving up to .32 Blanks - which have a pretty sharp report.
You've acquire quite a nice set of these unusual items.
I have an H&R made "Gas Gun", apparently made for the European market in the 1930s. It takes a .38 cal. gas shell and the cylinder bores are sub caliber (radically stepped down) at the muzzle end - it can't fire live ammo. It is one of the few that I have that is marked with the stamping "MADE IN U.S.A."