I think Listers are somewhat rare in the USA, but may be found where grid power was unavailable. Old farms, work camps, etc. So they might be found on Epay, estate sales and machinery auctions. Also sometimes in old engine classified ads like the Western Iron Trader etc. Although you might be diverted to some ultra cool old American made antique engine along the way....
I had an early ASHWAMEGH which was quite sandy, and ballanced well @ 940 RPM, but at the rated 1000 RPM was getting shakey, and any slight overspeed was jumping around breaking mount bolts. Perhaps they made are better now.
I run at a much more relaxed 735 RPM and like it alot.
The rebuild process to remove the sand was acually kind of fun, and I involved my wife and step sons to the extent that they might be interested. It was especially worth while during our 4 day blackout, where it warmed the hearts and fannies of ourselves and part of the extended family who were completely unprepared.
Scott E