REMARKABLE CA 1840-50 ARMOURER'S SQUARE

Very delicate square that tapers in thickness on each arm to 1/32". Remarkable that it is still in such outstanding condition. The corner of the square is about 1/8" thick. Both ends cut in a double ogee type pattern. Helmet logo indicating a likely German military/armourer origin. Initials E N punched into it. Exceptional.