Thanks guys.
Actually, I managed to pick up an Opemus 5 a with a Meochrom 2 colour head for free from the local photography school. So I'm going to pass on the II (unless of course you advise me otherwise). It also came with a Belar 4.5/75, although the lens looks a bit cloudy (initial observation only, it's in my car but I haven't had time to explore thoroughly - that pleasure awaits me tonight!), so I'll look for a better lens for it.
Ricus yes it was the gumtree ad, although I was planning to negotiate a lower price after seeing what they go for on ebay. Would your 39mm lens board fit the Opemus 5? It's actually missing the lens board or lens holder entirely - I have the lens but no way to attach it. So if your 39mm board will fit I would be most grateful and very happy to pay for it.
The other thing that's missing is the negative carrier, I'll see whether I can get one from Fotoimpex or on ebay. I also see that RK photographic in the UK sells aftermarket replacements for the Opemus 6 that they say will also fit the 5, although the price of GBP 55 seems quite steep. If anyone knows any other sources, I would be most grateful.
Thanks again for the help!
Andrew