Castrol R varnish removal...

[jerry thurston]

Nice oil, nasty varnish like deposits...

Any model car/ plane /boat enthusiasts, try some model fuel to get it off.

Expensive and not nice on paint as it's mostly Methanol (a constituent of paint stripper), but seems to be fine on glass fibre and great on alloy.

Mind you, would good old fashioned meths do as well as that is also natural alcohol based?