This is just a regular commercial cover. The stamps celebrating 100 years of German trains were current then and add little value.

The return address at the bottom left (typical then) makes for interesting reading.

Franz Oetter

G. m. b. H. (Gesellschaft mit beschränkter Haftung = company with limited liability)

Wäsche u. Webewaren (linen and woven goods)

Deutscher Fabriken (German factories)

Marienstr. 5 (Mary St. 5)

NÜRNBERG Nuremberg)

Fernsprecher Nr. (telephone no.) 27 1 54

The slogan is also of interest.

Reichsparteitag (Empire party conference)

der N•S•D•A•P (of the Nationalsozialistische Deutsche Arbeiterpartei = National-socialist German Workers' Party = Nazis)

in Nürnberg (in Nuremberg)

vom 10. bis 16. Sept. 1935 (from the 10th until the 16th of Sept. 1935)

It's addressed to:

Firma (Company)

F. H. Hammersen

A. G. (Aktiengesellschaft = Public company)

A. G. (Aktiengesellschaft = Public company)

Osnabrück

Thank you Oeb118 for helping me come up with description and title.