Thanks for your reply. I suppose you're right. No oil has leaked out so the chances are that measuring what's inside and maybe adding a few cc for what is left clinging to the parts should do it.
As for the machining and finish, I'm still impressed, although today I saw a bike equipped with some ÖHNLINS USD forks and they were so beautiful I stood there for several minutes just looking at them with my jaw opened!.
Thanks also for the other alternative names this bike sells as. I have quite a collection now. See the list on this thread:

http://www.mychinamoto.com/forums/showthread.php?t=76

I do wish the Chinese importers stopped messing about calling the same bike completely different names and models. It only muddies the water and makes it difficult to unite information from forums, locate spares, etc. In the Chinese bike world you have to be a bit of a detective to find out just who makes your bike...
There are people that claim that the whole Chinese bike thing is "just like the Japs 40 years ago...blah, blah, blah". Not quite. A Honda CB72 or whatever, was just that all over the world. If you need spares for a restoration or repair just Google that and the bits or technical help comes from all over the world.