it's not that different in a lot of ways. Yes, frame is different, due to the Bimota-style aluminium plate that joins the top rails to the bottom rails......that is about the major difference in the frame. Apart from that, well, they are both basic double-cradle tube-steel frames with twin shock rear ends, and normal forks.....I reckon all those extra goodies on that Moriwaki Zephyr, would get it handling really well - probably as good as any Rex with similiar mods ??
Then have a close look at the Rex motor, and then the Zephyr......there are a shitload of similiarities. I haven't done the comparison between bore/stroke yet - but from what I have read, a Rex motor is basically a water-cooled Zephyr motor. I don't know how accurate that comparison is yet (it's not.)......but if the bore/stroke figures are the same........

- well they could be a lot more closely related than we realise ? EDIT - nothing like it really. The Rex of course being a 4-valve head with bore of almost 80mm and short stroke, and the Zephyr only 2-valve with much smaller bore and longer stroke...
Billy - if only mate - I have plenty of other rims, most of them weigh a shitload !!
I hope I can find one, in no particular hurry - as Marty says - these rigs don't come up very often for sale.....maybe I need to grab that one from EnZed !!
some good stuff on these bikes can be found
here