We’ve had much discussion about the otherwise rather ordinary Pitman pens, on the subject of their origin. Consensus was that several manufacturers were involved over the years. Peter Greenwood has kindly drawn my attention to this Pitman which sold on eBay recently.
The photographs* show a fairly worn barrel imprint but the number 760 is visible. This was a model number used by Altura for a very similar – if not identical – pen sold under their own brand.
Could it be that most, if not all of the late 1920s and 30s Pitman pens were made by Altura/Waterman?
*Thanks to ashton_mill_auctions for permission to use their excellent photographs.
Goodwriterspens's Blog 
It’s an interesting question, but you have a snap of my 1920s Pitman’s College pen. It so closely resembles my Spot pen, that I suspect that ti was made by Mentmore!
Yes. I didn’t really expect this to end the debate!
Spot was a Mentmore brand
Yes, that’s how I made the connexion!