Just used mine yesterday, great fun, wacked down the neighbors knee high grass. They reduce cutting time by 10-15 minutes or more for your average suburban patch vs a 21 in push mower, and you can crash them in high gear if you're not paying attention. I dont have full 10000 units except for the one I use, a couple in pieces, I do have one available for the 924000 series, it's new old stock open box, but it wouldn't work on a 10000 without a lot of modification to the blade brake, or eliminating it completely, which would be unsafe. Plus they don't flexnfloat like the original....search forum for "clipper deck" posts, for pics. Plus it requires 15" tires/wheels, summer air filter, etc. I'm in Ohio.
To find the used original style survivor, you'd probably have to travel to Illinois Indiana Michigan Ohio PA upstate NY or East coast, as that's where most seemed to have been purchased