Some people try to fix rusty track, while others argue it isn’t worth the bother. But if you’re in the latter camp, you still have options besides trashing it: Make display shelves out of it.
My local train shop offers questionable track to his regular customers for free whenever he gets it, rather than trashing it or selling something that an unfamiliar customer might be unhappy with. I turned down a box of O31 track recently, then came to regret it a couple of weeks later when I remembered I could have used it. But that’s OK–he’ll probably have more next Saturday. Or the Saturday after that if not. I had plenty of disused track in a big tub under my layout anyway.
To make cheap shelves out of free or nearly-free track, you need something to mount it on. For that, buy fence pickets from Home Depot. They cost less than $2 apiece, and are nominally 1x6s that are six feet long. Cut the tops off to make them straight again, and you have a source of dirt-cheap lumber. One picket can hold 6-8 cars. Paint them a neutral color if desired. White goes with everything. Or you could paint them gray to make them look kind of like ballast.
Paint the track flat black if its appearance is objectionable. You can get by with cheap 97-cent flat black spray paint. The track won’t be very visible once the shelves are mounted on your walls, and from a viewing distance, flat colors make imperfections in the surface harder to discern.
Mount two lines across each of your pickets. Use O31 in back and O27 in front if you have both. The slightly higher profile of the O31 track can help the trains on the back track stay visible, or at least identifiable.
Now all that’s left is to mount the shelves on the wall, under your layout, or wherever else helps you keep the trains accessible without making your layout look like a bomb exploded and boxcars went flying everywhere.
Shelf brackets will cost more than the shelves, but you can mount your shelves on boards–I recommend using glue and screws for strength–then attach the boards to the wall, and the result will look something like this. You could even build the shelves groups of three, paint the mounts black or brown, paint the shelves gray, and the shelves themselves will resemble tubular track, keeping with the theme. If you like themes, that is.
Before I did this, I had a tub full of unused track under my layout, and a couple of tubs full of train cars I hadn’t run in years. Now that I’ve done this, the cars are out of the tubs and out where I can get to them, and I have two empty tubs, and another tub half full of curved pieces. Maybe I’ll make a helix out of those.