I had an idea to search through Haradin's auctions at Liveauctioneers.com, and see if "RS" turns up anything. I found this item, sold by a different auctioneer, but maybe it solves your puzzle, Tom?
A lot from Richard's Soldiers:
https://www.liveauctioneers.com/item/79625723_11-vintage-toy-lead-soldiers
From the description:
"Group of (11) Vintage Toy Soldiers, including: Set of (8) soldiers by Richard Herring, Scarsdale, New York,1977-mid-1980s, all marked 'RS',..."
Does that sound correct?
Prost!
Brad