Here's another CX ratbike for your perusal - the ''Ratracer''.
Its a 500 with home-made 2-1 downpipes into a centre-exit Peugeot car silencer,steel electrical conduit/Kawasaki dirtbike rear frame,
steel seat with canoe-seat ''padding''...
And plenty of matt black and hammerite paint.
Cheers, Esox