Since I last posted I re-built the top end, discovered the cam chain tensioner was in the wrong place, re-built it again then cracked the rocker cover and re-built it again! I think it's fine now...
Apart from that I've done very little on the bike, instead I've been devoting my time to constructing my new bike shed/Man Castle which should speed the building process up (over winter at least).
Your bike's looking good, have you had a sneaky ride on it yet?