Pics on Facebook page. Will put on here later
Frothy oil, not good, water in the engine, head Gasket or cracked block/water jacket somewhere allowing water into the engine.
Kerching Kerching £££££££.
Compression stroke pressurising the cooling system and induction stroke drawing water into the combustion chamber and exiting it out the exhaust.
Engine full of water/oil foam.
I reckon if you feel the bike is worth it (Condition) a lump from a crashed donner bike might be the way to go ,as you will have all the cases and stuff if any are damaged on the donner lump.
Good luck rw keep us informed.
I hope I am totally wrong but things are pointing that way I'm afraid.
tommy