The model would be m1924/25, the first one with longer action. It was the first model which has been chamfered to many different calibers, .30-06, 7x57, 7x64, 8x57JS, 8x60S, 9.3x62mm and even 10.75x68mm. It has steel butt plate and only wing safety. Could you send any fotos ?

By the way, m1952 is the first model with swept back bolt handle, named GK (= Gebogene Kammer)