Was doing a few jobs on the van today and sods law kicked in

Went to drive it out of the workshop to find the throttle sticking. Checked the pedal end..loose, checked the carb end (2 litre air cooled) loose. Ended up dropping the fuel tank to find the cable has worn through the outer casing on a slight bend above the fuel tank. This casing houses the cable from the pedal to a join half way down the van. Its knackered so stripped it out of the van, now on the look out for a replacement.....Any ideas were I could find one or piping similiar? Its hard plastic about 8mm and the inner hole where the cable passes through is about 6mm and Im guessing its about 2.5 mtres long. It must of happened to somebody but say that my van is an 1980 model so its got 30 years of hard use behind it...
I think I will end up removing one from a scraper but would like to replace with new if I can.
Just pleased it happen now and not half way up the A1 on a Friday night
Thanks in advance...
IAN
Mmm what's that strange smell from my exhaust...