I recently bought one on ebay (I am sure you saw this) which is actually a very presentable machine, very well built with a solid wood laminate cabinet and more chrome than a Jennings Govenor. The mechanism is very similar to a mills/sega, but has no mlb or sega number markings.
There are two more Mills variants, I assume made by the same company as my as the cash trays are identical with the dual ashtrays built in. These though are electromechanical, where as mine is completely mechanical.
Any information would be appreciated as I have assumed these are British built variant using the Mills name (even the owl logo)