thanks fellas,the guy was happy to repay me,he is "moto retro",he has all the genuine parts books and its not 500/550,he bought old stock from a closed business and thinks it was tagged wrong there,he was glad he didnt mail it to someone,hes only 70 kays away open road travel so it was no big deal for me to drive back,hes rubbed out the code and it now wears a question mark.thanks for that link oldschool thats handy
http://www.motoretro.com.au/index.html he has 2x cylinder 3, 500 exhaust pipes brand new #18400-323-070 $100 each.