While the CBF was having its charging problems it also started gushing oil.
The oil was pouring out of the pipe to the oil cooler. The fittings had corroded & cracked. Replacement hoses are expensive but I've bodged this sort of thing before. I cut the hoses and spliced in a length of rubber tubing. The only cost was some Jubilee clips. I bought real ones as the Chinese copies are poor. The pipe was once part of a washing machine.
Will it hold? - I think so. The oil cooler never gets very warm and is probably unnecessary in the Scottish climate.