Case Colour Protection?

[Grouser]

Read somewhere on the net that you can preserve the case colours on older guns by coating them with a thin coat/coats of True Oil. Anyone know this method????
Thanks!

 

[gunasauras]

I've heard of lacquer being used, but not tru oil.....

 

[Mudpuppy]

Lacquer would be better as Tru-Oil would give a yellowish tint that would make the metal look dirty.