Went on another really cool field trip to the Western Antique Aeroplane & Automolible Museum in Hood River Oregon. Didn't have my good camera so don't have many pics of the huge number and variety of 1900-1950's cars, planes, guns, memorabilia, etc.......will go back and add better pic to the thread.
Pretty cool.
Sight for a SBD/TBD rear machine gun