AC Gilbert did make HO trains and got into the business fairly early compared to Lionel. They made them from 1948, after ceasing O scale production, until 1963, when they stopped making HO and concentrated on the remaining demand for S scale and the new rage, road racing. The company really died in 1961, when A.C. Gilbert, the founder, passed away. The family sold out their interests to the Wrather Corporation in 1962 and American Flyer began a five year decline to bankruptcy, making poorly designed and manufactured toys of all description. The last train was made in 1966 and they struggled into 1967 selling everything from talking dolls to R/C cars. It is a classic business school study case of what happens to a company where one man is really the idea leader and he had no one with his imagination to succeed him. I chose A.C. Gilbert as my case study when I was taking classes for my MBA and it is really a sad story, with many parallels between the decline of A.C Gilbert and the general decline of American business.
Now, after my executive summary of my MBA study
, is it a complete set and still in the original boxes? Depending on the type of locomotive, number and type of cars, condition of the boxes, and if all the original paperwork, including the warranty car, is still there, you may have a real winner. AF made two levels of HO trains, one that was all made of plastic and poorly detailed and another with pretty well done diecast engines and well detailed plastic cars with metal trucks and wheels. The first was made for the department store trade at the Holidays and the second was meant to be sold in hobby shops to model railroaders. The department store sets are fairly common but can still bring a good price with everything intact and in good shape. The hobby shop sets, especially if it had the Pacific steam engine, can go for well over $1,000 in excellent condition. They made a set for a few years with a GP-7 and four freight cars and the Pacific with three real stainless steel Budd-type steamlined passenger cars. The set also included a bunch of scenery and operating accesories, like airport beacons and an operating coal hopper dump. I think these were only sold from 1956 to 1958, when the recession of that year killed the market for high end trains sets. I wish I still had all the paperwork from that MBA study (including most of the Gilbert catalogs from 1946 to 1967, dang it) but I think the double set sold for about $100, which was a staggering sum to pay for a trains set in those days. If you should be lucky enough to have one, it goes for $5,000 and up, or at least did, before our present crash. Check e-bay and see if anything you have has sold there for an idea of value. I don't think you will be able to retire on a train set but I suspect that, if you want to sell it, it's certainly good for at least a couple of really nice present day HO locomotives.