Thanks Arfon and Baz for the inputs. I think this thread can be useful to forum members in the future with all these very good infos.
I finally cut my stainless tubes and bring them to a professional welder I know with my motorbike muffler. He did a very fine job in one day, for only £30, which is much cheaper than a stainless wire roll (and a new gas mix!)
Here is the result, and I'm very happy with it.
2013-12-03_10-50-07 par
Voucht71, sur Flickr
2013-12-04_14-02-04 par
Voucht71, sur Flickr
2013-12-04_14-38-14 par
Voucht71, sur Flickr
More pictures and a follow up about the muffler mounting at the end of this thread:
http://www.haynes.co.uk/forums/showthread.php?t=12974
Thanks a lot to all of you for your help
