M50 Engine (or parts) needed

I bought a M50 engine about 18 months ago with the idea of putting it together with all the spares I have for a prefeatherbed ES2 to make a road going bitsa, but a visit to the Telford off road show in Feb found me at the Rickman stand, one thing led to another and the idea of a Norton Metisse that is pre 65 scrambles elidgable was born! 

When I bought the engine I was told it had been rebuilt and was ready to run, it certainly looked in good shape from the outside and through the ports, anyway it was duly sent to Mike Pemberton to have him breath his magic on it, sadly when he stripped it today all was not well, it looks like the engine had been full of water at some time and everything was badly corroded, who ever “re built” it had sand blasted everything and put it back together regardless of condition and without cleaning the blasting medium from the engine. The crank had also been cleaned with an angle grinder and the rockers blasted without removing them. fortunately the head and cases are usable ( and the barrel and piston, but I won’t be using them)

So the net result is the head and cases are usable but not much else so I need either another engine or bottom end, and fairly quickly if I am to get this on the track before the end of the season.  So if anyone has, or knows anyone who has a spare engine for sale can you let me know?! 

Cheers Dan