I wouldn't woory too much over it. It happens sometimes, and someone will find another big stash of them. At a higher price! Many other motors can do as well or better, just less documented.
Why Ameteks? Because they used to be common for $10, and there are a lot of people documenting how they got it to work. Thats all there is to it. G-
Mark, probably they didn't come up into your search because you were somehow redirected from www.ebay.com to ebay UK, or ebay AU...or other country's ebay version, then you performed the search and there were no motors listed from that ebay version.
Sometimes you log on ebay.com and while you browse the web site you get redirected to ebay.co.uk or other ones and you just don't notice you are not in the .com version anymore.
if you're on ebay.co.uk and search for 'worldwide' , then it only shows listings that list postage to UK , people who dont have it listed may still be able to if you ask nicely :)