[Gunner]

Maybe there's some reason not to, but wouldn't real sidepipes - with the inner ends cleverly covered up - be easier and more realistic than trying to whomp up facsimiles? I doubt you'll save much trying to fabricate several sets when you could put in a group order from any supplier. The difference between just tubes and the collector point and muffler guts isn't going to be much.

You could also get away with chroming the pipes, since they'll never see heat. That would let you buy cheaper steel uncoated pipes and then do any suitable paint, powdercoat, ceramic coating or chroming. MUCH cheaper than stainless...

For example, Shell Valley has unfinished pipes at US$595 and chromed ones at US$970. Not bad, especially if you get a group deal on purchase and shipping. There may be better prices out there, too.

Just a thought; cheers!