Thanks Ned, Grandini was the up market side of Youngs cycles when they were in Lee High Road near to Lewisham. In fact they sponsored, I believe, an independent bunch of guys and this must have been in the '60's. I would estimate the bike to be a '60's manufacture, the under B/B cabling is just something that was done to modernise the frame, and not by me I would add. In doing this unwanted act the original frame number has been ground off so there is minimal chance of any accurate dating. The seat tube and rear stays lug was, I'm told quite unique to the Grandini although there was a similar affair on some top of the range Carltons. The additional pic which was taken before I painted the frame clearly shows this lug arrangement.
I would add the bike is super light and with those 28's it fairly flies along.
Keep safe, cheers.