Ludwig,
I'll PM you later today with the ref:#.
I'm bailing on this one. I checked the reg. # with DVLA and it's come back as "not listed". Due to the fact it's a 1970's # and I suspect the bike is quite a bit older than that and NO chance of an "owners club" date service - that's me.
The seller now talking £500 as a buy it now - that's £200 'ish more than I was going to bid and probably £400 more than it's worth ! He says he'll let the auction run.
On the bright side my pal in France [ we think it's French or Belgian ] says he's seen quite a few like this around his village [ maybe the same ] and they are around the 150 euros mark - a bit more like it.
The rear m/g / enclosure looks remarkably familiar for some reason.