I have one....I'll post some pics here in the morning. The pipe itself looked to be in great shape. The stainless braiding is similarly discolored from use like yours. I believe the insulation material between the stainless braid and the pipe itself has deteriorated or crumbled.
So, I'll add a bunch of pics tomorrow for you to see and go from there.
I also have the factory downpipe from the same engine....an '85 140 block complete engine I had picked up for parts.