I have recently had a couple of exhaust pipes manufactured locally ( in Birkenhead ) in stainless steel, one for my project bike, replicating a '60/'70's British single and a replica of a DR 800 hi level pipe. The project bike pipe is on and fits well, I supplied a pipe made from bends and straights welded together and it was reproduced in one piece on a mandrel bender.
The only problem is that they make car exhausts and I think the smallest OD is 1 1/2", mine were 1 3/4" OD so they couldn't copy the XBR system, but others should be possible and the cost was very reasonable.....£45 in polished stainless, but the cost may vary according to complexity.
Jerry Darlington
Cybrand Ltd ( PECO )
Email: sales@cybrand.co.uk
Tel:0151 666 5366