We were down in Charlotte visiting my wife's youngest sister when I was remined of some artifacts that they are keeping. You see, my darling wife the grand daughter of MGEN Rupertus, USMC. Anyway - I was given 2 handguns to identify & restore. One is a .45 (that's for another thread). However, this little guy I cannot ID:
The slide length is 4.25 inches and from Butt to top is 3 inches.
Here's a closeup of teh engraving:

WAFFENFABRIK MAUSER AcG OBERNDORF A.N.
W.T.P. - 5.35 - D.R.P. U.A.P.
All I know is it's A mauser & it's tiny. Perhaps one of you with better Googlefu can help out.