Prewar American OO (1/76 scale) was established to accommodate the larger AC electric motors needed at the time. After the "big one", technology had progressed and model makers had perfected the DC small motor that would fit into the HO (1/87 scale) units and OO went the way of the Dodo bird. Lionel (and everyone else for that matter) seems to struggle in selling S scale, I cannot imagine the cost of remanufacturing OO and the VERY limited market it would hold. Lionel only manufactured one locomotive and four freight cars in OO. Competitors like Scale Craft, Nason, Schorr, et all had a wider variety but they were all kaput by the mid '50s and their offerings would be considered very crude by today's standards unless one wanted to spend undue hours super detailing them. I have a few collector pieces in OO and in a perfect world would LOVE to see it reintroduced but we have O gauge manufacturers leaving in droves, I cannot imagine a "new" scale coming into the mix. In my years of playing with toy trains we have lost Marx, Atlas Tool Company (Rivarossi), Williams (Jerry's company, not WBB), Frank's Roundhouse, Crown Model Products, AMT, Weaver and now Mike's not to mention Lionel changing hands at least 4x. I am sure I left someone out of the mix, I apologize in advance for that.