I agree with Dave along the line that I find a lot more cans and gas related items in the local antique shops now, and that it's probably been these shows that have made antique dealers and the public take note that they are collectible and they do sell. Mind you some are better left for the scrap man, but at least they are recognizing the market for gas/oil items and are making an attempt at saving it. I've noticed that it does not last long and sells in almost any condition in the malls.
A good fraction of these dealers never would have dreamed of selling this stuff in their booths years ago. I find it funny to see grease cans in "fu fu" pink booths with white lace doilies, lol! I'm glad for it, as usually they don't know what the items are truly worth, so it works out for us collectors sometimes.