Well after a lot of searching for bits and bobs my s-wing lives for a bit longer(hopefully a lot longer).
Has had new crank and bearings complete unit bought as was easier, rather than try to work out wat bearings i needed and where to source from......
New piston and cylinder kit complete as piston had decided to scrape side of barrel......
New Gasket set and seal set.......
Downgraded spark plug to standard 1...and put in new original Honda rollers......
Cause of damage unsure, but piston looked like it had gotten heated some how and loads of burnt deposits on it......
Thanx to all for all the advise given ....here`s to another 30000 miles b4 it breaks again.......