Wanted: 50-53cm steel track frame

Hi there,
I'm looking for a lightweight steel track frameset somewhere within the 50-53cm size range (well maybe up to 54), ideally under £200 but could go higher if it's something special or the tubing is better than 531. Colour doesn't really matter as I might want to respray it later, but I'm particularly inclined towards blue. Please let me know if you have one knocking about. I'm based in London.
Thanks very much
Tutu

I have an as new cinelli gazetta (the kind with the superior forks) lime green. 52 square. Columbus tubing.

£250