Your best and cheapest solution may be to use a VTN-200 heat shrink to
cover your standard PVC sheathed multicore. VTN-200 shrink is chemical
and oil resistant and easily available. eg. Ebay # 251726064642 Might be
an idea NOT to shrink it as it is more flexible unshrunk.

Thats a great idea. Ill check it out.

Thanks.