All of the former Classic Warships model products--kits & detail
parts--are now the property of Yankee Modelworks, who have some of the
items in production. I don't know whether they're producing the S-boat
props, but you can contact them at:
http://www.yankeemodelworks.com/
Cheers,
John Snyder, White Ensign Models, http://WhiteEnsignModels.com