I was about to spend $1500, but...

[YellowDog]

Look at this: http://www.toolparts.co.uk/acatalog/4_Stroke_Exhaust_Baffles.html

Insertable and removable baffles for any exhaust.

Anyone have experience with these?

[hayd3n]

looks good

[birdhandler]

I wanted some sppeb bleeders the shipping cost was 45 pounds !!

[vifferman]

Meh.
Look, if you measure the ID of your muffler(s) you can get some made yourself. That's what I did. But DON'T try explaining to the muffler shop what you want, because many of them are halfwits, and you'll never get past the bit where you explain it's for a bike (even at a bike muffler workshop! The eejit there wanted to cut my mufflers open to see what was inside - $250 before he even made anything! And this was AFTER I'd explained what I needed!).
Draw a diagram, with measurements, take it into someone who advertises they make mufflers or zorst components, and say, "Here - make this, please."
I went to Woolf mufflers, and got two made for the FahrtSurm for a total of $60, based on a picture I'd seen on the Interdweeb of the Staintune restrictors. The Staintune ones have a threaded hole on one side, with an allen-head bolt that screws in, with a stainless washer and spring washer underneath. However, on the FahrtSturm, the ID of the end of the muffler where a previous owner had cut the end cap out was a bit over 50mm (maybe 52) because he'd used a 50mm or 2" holesaw. So, I just slathered the outside of the (50mm OD) restrictor with high-temp black silicon, and slid it in. Worked brilliantly, and passed 3 or 4 WOFs like that. If you get the baffle/restrictor made with a long 'tail' on it, you can cut bits off until it sounds right (just note you can't glue them back on!)

[YellowDog]

I can't imagine shipping being much for such a small item, but will check first.

[YellowDog]

OK - Just bought one. GBP2.50 shipping to my Dad's house who will post it out for free (to me).