The Tin Man, a forum advertiser, reconditions used Lionel track to like new condition. If you don't want to do the work yourself, his products are already cleaned, rust free and ready to use.
You could also remove all rust from old Lionel 0-027 track by soaking them in a bath solution of 24% molasses and 75% distilled water for a few days. I doubt if the rust bath removal process would work on Gargraves or Ross track though, as the wood would warp or probably not take well to soaking in a water or chemical bath.
Actually I like the rusted track look as it looks like the side rails of real track.
