ORIGINAL: Hobbsy
I think I bought that header and pipe from Tower years ago. Pipes don't work all that well on Diesels because the exhaust is cool compared to a glow engines exhaust. With a MVVS quiet muffler the .46 conversion turns a Graupner 12x7 in the 9,300 rpm range.
That header and pipe look like Macs to me; Tower sold 'em. Doesn't look like you ever used it the pipe, because it's still full length. I have some of them. Also, the wrench looks like the one that Fox put in with the Pylon engines. Ah, history....
CR