All is well!
Have checked inside the bearing chamber and there are two 5 pence piece size holes which ave been filled with resin,metal repair putty etc,and the area on the top of the engine simply covers the lot to eliminate any leakage of compression etc,the majority of the damaged area inside the engine is still metal,so i have put a layer of araldite over the whole damaged area on the inside,to seal it and prevent anything breaking down and falling into the big end.
shall possibly be trying to get it to run again tonight.
(bit of 2 stroke in the carb)
and see how the clutch etc is working after its replacement,then a restrip to check and tighten everything,then a few more jobs befor the MOT….