I also have this screwdriver.  Well, it definitely has a ground down flat
head, but it sure is stout to be simply a screwdriver.  My question is
whether you think it is a shop made tool or maybe there are more of these
out there?  Doesn't seem to be any sign of rust on the steel, does that
mean it is stainless?

Thanks for looking:

https://www.flickr.com/photos/122649122@N.../albums/72157707690266144

Jason