Don,
I've been lurking around this subject for a few days now, mostly because I'm very interested in the possible existence of a French FT-16 with a black endbell, but also because I didn't feel like I had a lot to add to the discussion in the way of new or useful information. I've been waiting for someone to drop a shoe.
On the other hand this is a discussion forum. so let's discuss.
I have no proof that a French FT-16 with black endbell ever existed as a product sold by French, however I do have some clues:
(Above) A Cox Competition-I motor part number 4000. Note the gray lead wires and wide solder tab (where the lead wire is attached).
Next, a Cox TT-X100, part number 4012:
Note the red and blue lead wires and wide solder tab.
Now, my (ebay) photo of an (alleged) French FT-16 with a black endbell:
Note the red and blue lead wires and wide solder tab.
Cox is the only American name brand I know about that sold Mabuchi FT-16 motors with black endbells. The "fly in the ointment" is that these motors had plated cans (chrome or nickel), whereas your example has what appears to be a gold painted can (repainted white), which would of course suggest Russkit. Russkit never, that I've ever seen or heard of, sold FT-16 (Russkit 22) motors with black endbells.
Is it possible that French sourced these parts (gold painted can and black endbell) separately either directly from Mabuchi or through a third party? Yep, here's a photo of a gold painted FT-16 can (suggesting originally made for Russkit) in a Tradeship package:
Tradeship also marketed other cans, including the rare and sought-after Igarashi/Pactra X-99 five slot can:
Maybe Tradeship marketed the leftover Mabuchi gold painted cans and black FT-16 endbells directly to French? I dunno... It's a mystery...