MOT, noisy pipes? Why worry, Whyworry.
As Ray says a lot of it goes on the testers discretion now, as long as the can hasn't got a 'for race use only' stamp on it.
Even then, all they wanted to see on my last test for the ST was that I'd got the original cans.
On the other hand my 888 has got cored cans and they're loud even though they's got all the e stamps you want on them. If Fordie was an MOT tester it would NEVER pass.