Cheers Pat, There are several schools of though regarding the YEIS 'boost bottle'
1; To tune your bike up take it out, it's Yamaha's underhanded attempt to restrict your bike.
2: To tune your bike you need to fit a 'Boost bottle' as developed by Yamaha back in the 70's
i'm with 2:, I dont believe that Yamaha would have developed these things and continued to fit them to their bikes with extra production costs if they are of no benefit, they certainly were developed as a tuning aid, never as a restriction. The benefit may be small, even un measureable but i dont believe they are detrimantal.
The silencer is a different type altogether, its just a perforated tube with exhaust packing, quite commonplace. But the original is a different story, it is full of tubes to divert the exhaust gasses this way and that before it exits, there is a name for it that escapes me at the mo (its my age y'know)
I would recommend you buy new or used another rather than mess with the one you have.
Vez will post pics but havent taken any, it was going dark when I finished. As for the stickers yes i phoned them and they are all like that now so i'm past caring, still looks good.