My first steel helmet

[mclakic]

does oiling have any damaging effects ie to decals etc was oiling encouraged to limit further rusting?

Oil will not demage decal and will stop further corrosion. But you have to be precosious with using oil to soft dried leather on liners. It can be used on black leather otherwise, brown or white leather will become much darker.

[davejb]

All oils contain a certain amount of water and over time the oils will soften paintwork and can alter the colour, as for the decals it can have the same effects, and if it gets under the decal it can start to lift it from the surface, at one time people used to oil their helmets but i believe that practise has now become obsolete