Chinamos are (or at least were?) available throught the Vin***t spares scheme as a substitute for Lucas/Miller units.
They are of Chinese origin (as the name would indicate

), I'd guess Chanjiang (Chinese version of the BMW R71, aka Ural, aka Dnepr, etc.). So basically should be an old Bosch unit.
IIRC they got 80mm in diameter, different drive and mounting system, so deffo not an easy, direct replacement. Then there's the non-original appearance. I for one wouldn't put one on any of my bikes, let alone on a Vin***t (if I had one).

Here's one on ebay:
http://www.ebay.com/itm/DYNAMO-CHINAMO-ADAPTOR-RING-ET202-REMOVED-VINCENT-TWIN-/230685984634