I have spoken to Dave Swarbrick [http://www.swarbrick-racing.co.uk/] who says while they are no longer listed on his website, he still has the plans for MC21 silencers and is happy to make them to order.
Off the top of my head, I am pretty sure the bolt pattern and orientation is the same across all models, but it wouldn't hurt to confirm that with him first by making a template for an MC16/MC18/MC28 if you require silencers for those models.
He makes both carbon and alloy silencers, although in my humble opinion, the alloy versions are a bit too "old skool" for the 88-97 NSR. They wouldn't look out of place on the MC16 though.
I ran his carbon silencers for a couple of years on my MC21 before fitting my full Ethos system. Be aware that they are proper "race" silencers, and as such are "no thrills". They are fully rebuildable, but there's no heavy gloss to the carbon, and the outlet is simply painted mild steel. They sound and perform great though. I will try and find some photos of the carbon silencers fitted to my MC21.
Please contact him directly for prices and shipping details, and please mention NSR-WORLD.COM if you call/e-mail him.
_________________
Andy.
NSR-WORLD.COM
Please keep all responses to Forum posts on the Forum so that others may benefit.
Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.
Check us out on Facebook! Please "like" our page!