As I stated on the Mauser forum, I don't think this is a modified DSM 34. The use of Deutsches and Sportmodell on receivers and barrels was common during that time. You will find in the back of Jon Speeds book on Mauser smallbores, several models with one or the other name. The DSM 34's will have both. You said on the Mauser forum that the receiver only said Deutsches Model.