No, a friend of mine who builds mostly large drag racing engines did it for me.I'll find out what company supply the stuff,probably an American company.

10 hours ago, fantic tom said:

Looks good did you do this yourself?

Hi Tom, Had a good look at both an old used piston and a new piston, seems taper on new piston (difference between top and bottom) to be 8 thou. Whereas the old used piston. the difference is 16 thou. I also had an interesting conversation last night with the guy who had re-engineered his piston. The long and short of it.....He made a 3/8th thick dural/alumium disc, after heating piston for 20mins in oven at 200c, took measurement (while hot) at the piston inside register and made a size fit disc (fitted cold to the hot piston) cooked again at 200c for 30mins then left in oven overnight (to cool slow).  I suppose you could have a measure up, to see how much your own piston has worn/distorted, and may help in getting a fuller idea as to the sort of clearances involved. 

Thanks guys some great intresting info.