Just realized my pic of the case did not turn out. Last pic shows numbers in top of case but very hard to make out. Cheers Brian
'Dienst Glas' ( service glasses ) are military but I believe WW1 era.
The stamp could be a regiment i.d.
The label says ( roughly ) "Instructions for use for double telescope"
" When you're chewing on life's gristle, don't grumble, give a whistle "
These could be unit marked from the look of it JR62 if I am reading that right and they look ww1 to early 1930s to me
Doesn't 'D.R.P.' mean 'Deutsches Reichs Patent', i.e. post-1933?
Deutsches Reichspatent, was a "proper" patent, assigned from 1877 until 1945