i got it from les at mainly maico, i first saw them at
http://www.x-tremevintageyz.com/ les is having some difficulty with his site and the product listing is not showing so you cant see the pics of the exhaust unless you view the above web site, les at mainly maico has some brilliant products that are NOT mainly maico and if the web site gets up and running its worth a look
buy the way the seat is being recovered with a replica seat covering this should make the bike look great, hope to go for a ride mid week and see if i need to jet the the carby and to see if or what power difference it has , i gave the original exhaust to my mate as his is rooted, anyway shall let you know how pleased i will be once i get to ride it , the seat should be done buy tuesday, and the front forks as well.
cheers BONEHEAD