Solo Seat Fastener 
  Is anyone able to give me a part number for this fastener so that I can order some. It was used on the solo seat unit on my 95 SS with a superlight seat. Flange is 22mm. Thread is M6 I think. 
 My dealer can't help, they only have the 2 piece fixing listed apparently and not the 1 piece with plastic washer that I have. 
 
 Thanks.