Interesting - I'll take a look at that. Part of my collection is kept in a walk-in attic which is slightly damp as it is unheated, so the guns do need protecting. I've been using a furniture polish called 'Briwax' - it's some kind of hard wax already partially dissolved in a solvent. I add more solvent (lighter fluid) then apply a thin film with a clean rag, let it dry then give it a quick buffing up. It seems to do the job, and does actually make both metal and wood look good. If necessary it can be quickly and easily removed with lighter fluid.