All About Aurora Postage Stamp Trains
American Train Club Order Sheet
American Train Club appears to have been a division of, or an alternate name for, C.J. Bubla, since both businesses have virtually the same mailing addresses. Also, this order sheet includes C.J. Bubla's "PST Special Sets" as well as everything Aurora originally sold, and then some; it would seem some bus sets were opened up and the contents sold individually—at least on paper. They also bundled track together into two "Track Paks" that included grass mats, trees and more, and sold F9 diesels at deep discounts. There's no date anywhere on the sheet, but I'm guessing it's probably late-1970-early-1971. Pages link to larger images.
American Train Club ran a half-fare promotion in the November 1970 issue of Signature magazine. There's also zero information to be found on the American Train Club—a web search will only bring up this page.
With thanks to Bob Williams for the order sheet.