[David Dunlop]

You are right, Richard, but my surprise was more that I finally found one of these particular marks and that was compounded by the fact it is yet again different from other marks found for this company.

To date, on various pieces of kit, I have found Canadian Marconi Company have identified themselves with any of the following markings:

CMC
C.M.C.
CANADIAN MARCONI COMPANY
A small round circle with C.M.C. In the middle, stamped into metal parts.
A small round painted circle with C.M.C. In the middle stamped onto the surface of parts in black, yellow or white paint.
C.M.C. In yellow paint stamped onto the surface of parts.

This oval with a more script style of lettering CMC in the middle is now a new addition to that list.

Yet another puzzle. If these connectors were a prewar design by a third party company, I would expect that company would likely have patented the design. In that case, if CMC were making them, I would expect to see some form of “Manufactured under licence by CMC” acknowledgement somewhere on the item. Nothing like that found so far.

Also odd, if the design of these connectors was a CMC thing, would they not have applied for patent rights? If so, the connector should show “Patent Pending”, or, “Patent applied for” on it somewhere.

Of course there might be another factor at play here. During World War Two were patent rights adhered to or suspended, for the sake of getting production of items running as quickly as possible? If that were the case, one might only find patent references on products made by the original inventor as those dies etc would already be made and in use. A new manufacturer may not bother with those details simply to save design time and just put their own iD on the product.

Damn! Too early in the day for so much thinking. I need to rake some leaves in the back garden now and brew up some tea!

David