Hi I have allready started doing one two years ago as you will find out it is not a easy task I wish you well . The 500 single you refer to was loaned to a italian rider and raced in home events in the mid 60's it had I believe the same bore x stroke as a bsa b50 84x90 allso if you want to race it in the uk the acu will not let you run with a dustbin fairing! Regards rodders.