Traderyoda, no photos; you stated concern about the wheels that you would expect to see mag hub and 19" front. Now, first off there is a lot of information in the two Rickman books, but not to details as I would like, plus several hundred serial/order entries are missing. With the information I can amass from personal observation and the books I have an idea on the hub deal. It goes like this; mag hubs were available early 1967. Before that British Hub Company Motoloy 6 hubs were commonly used by Rickman and continued in use to individual orders. Motoloys are displayed on the Rickman brochures right up through the 1967 model release. Some individual kit builders or orders used REH (as seen on the #66x BSA above), others QD or many types of standard British hubs. The 1970 Rickman micros both Hodaka and Zundapp came with mag hubs. The 1971 and up Hodaka, Zundapp, and Montesa had the new Rickman aluminum conical hubs. I've seen both mag and aluminum on the Yamaha kit bikes you referenced. The 4-stroke MK III and MK IV kits or complete usually had mag hubs if they came from Steens. Others used whatever they had I guess. Now, to the point; the British Hub Company Motoloy 6 that is on the back of your MZ is probably the original fitment. Here's why; The Motoloy 6 is a cush drive hub. Lynn, an ISDT guy would have liked that to take the snatch out of the chain improving transmission, chain, and wheel spoke life. The front wheel would be a 21" for its better trail manners and light handling. The front hub well, if that MZ was made after 1970 the Rickman aluminum conical hub would be a natural choice and if made before 1970 it was probably retrofitted from a Motoloy to that Rickman aluminum conical hub.