The sales ad above is currently the only paper item I can find on this stapler at this time.  It's from the Keystone Type Foundry, which is from Philadelphia, PA...the same place the stapler was made.  The sales ad refers to a Yarger No. 10, but the one we have is a No. 9....not sure what the differences were between a No. 9 and No. 10.  At this point the stapler doesn't work...but believe it's only because I don't have the correct sized staples.  Full restoration of this piece will happen someday for sure.