We don't know the reason for selling and it'll be for a good reason BUT this one can't go, surely?
If it means handing it over to someone who will keep it for you for the time being go for it. If I could afford it I'd buy it from you and wait for you to buy it back from me (I couldn't ride it anyway - I think the toptube is at my chest height!).
I can't think of many other bikes that are as rare as this one.......
I'd be quite sad to see this bike disappear into someones garage never to be seen on retrobike.co.uk again. :cry:
Just a hypothetical question, but if you were to keep this bike what parts do you need to finish it off to your desired specifications? It seems pretty close to completion except for the missing MRC bars, and some brake/derailleur cables.