Replacement down pipes

Anyone know good supplier of replacement downpipes for 79 Z750 twin? they are needed for standard 2 into 2 system

I suspect if anybody still makes an exhaust system for the 750 twin, it would be Jardine. If you still have a pipe , a high quality custom exhaust fabricator should be able to replicate it. I would avoid common muffler shops as they will likely not have small enough tubing and cannot make mandrel bends.