Found a couple of Plombs at the flea market, a Combo 5/16 Pebble 1210, and a 1126 1/2-7/16 DBE.
Now for the odd ball.
It's a 5/16, 1/4 open end with a 1/4 6 point box stamped in the middle, and two copper feeler gauges riveted on the 5/16 end. The feeler gauges are marked "For Magnetoes" and "Sparkplugs". There is a logo on the back that I think is the rounded H-B.
Herbrand? But there is a figure in the middle that's too small to make out. It also could be an A-B (American Bosch?)
Any idea, what magneto this might have been used for.
I know some pic's would help. I'll work on it.