Gents - looks like around the 73-78 period the clutch push lever was fairly common and maybe only the YZ had the plastic one - XS, TX, TZ and RD of varying sizes had a metal one. Freaky - some had a short arm whilst others had a longer arm - probably as John was talking about. Lots with differing model number 483, 447 etc but the same 16340 descriptor number. I think I will buy one of the longer metal ones as the price difference between these and the YZ ones is unbelievable so worth a try.
Rossco