Thanks for the help in identifying all the parts and narrowing down the time period, it makes everything a lot clearer!

I'm 6ft 1 which usually means an xl frame or 56cm + but I have sat on it to see how it feels and it seems to fit me well. I'll defo give a mesure tomorrow morning to confirm it's size. In terms of the expense, what's the general sum I would need to put into this to make it roadworthy? I appreciate it's difficult to do just through pictures so no worries if you're not able to!

Thanks again for the great info and help I really appreciate it!