Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Marked with the D.R.P.
Reversing
Maker ?
Valve gear ?

Sorry, I’m having problems posting photos

Pics would help 

D.R.P. simply mean Deutches ReichsPatent (a nationwide German patent), and would fit quite a few engines through the years.

Correct - "D.R.P" (the three dots are important to distinguish it from "Deutsche Reichspartei", e.g. dating back to the days of the Weimar Republic) stands for "Deutsches Reichspatent". This label was used between 1877 and 1945, when the "Reich" (= Empire) seized to exist. Since 1949 DBP (Deutsches Bundespatent, German Federal Patent).
You often find "D.R.G.M." = Deutsches Reich Gebrauchsmuster" on German products. It was used between 1891 and 1945, the "little brother" of the patent, protecting special features or labels.
These are often confused with brand names or labels by non-German speaking collectors (which is understandable if you compare this with "EPD" or "GC&Cie). The same happens with "Gebruder/Gebrüder/Gebrueder" (simply: brothers!) or "Württemberg" (the name of a former German Kingdom, south-west Germany. This name is sometimes misspelled on Märklin labels!!!).