Paint...

[Richard Farrant]

A common method we have used for years in England, is a water displacing preservative / releaser called Duck Oil (somewhat similar to WD40), no silicones in it, easily washed off if paint touch up is needed.

The benefit of Duck Oil, is that it can seep under joints in panels, brackets, etc and helps stop rust from forming. You just spray it on and wipe off, it rejuvenates old OD. Looks very shiny until the fluid evaporates then has that fresh paint look.

Also, I always use Semi-matt shades as they are more durable, a dead flat matt will absorb oil spots or streaks and it is impossible to remove.

Richard