Those molds are available now from Castings, Inc. The company is a direct descendant of the Rappaport Brothers' legendary Home Foundry. You can see their catalog online at
http://www.miniaturemolds.com/index.htm.
Along with the Civil War molds, they have a line of 54mm figure molds, made of metal, to cast figures that are copies of some of the old King-White/Reeves Napoleonics, as well as molds for the old Gebr. Schneider toy soldiers. They also have molds in silicone rubber to make knights, chess sets, and classic toy soldiers (Coldstream Guards and Highland infantry, which look like they were originally copied from Britains and other classic British hollowcast makers' figures).
I had some of the King-White molds but gave them away; the detail was a little too soft for my liking. But I still have some of the silicone rubber knight molds, which had decent-enough detail to them.
The also sell mold-making supplies and tools, but I haven't bought anything from them for years. The last time I did, they gave me a bait-and-switch on a mold clamp. They told me that the one I had ordered was discontinued, and they sent me a different style of clamp, very impractical in its design. I would rather they had just given me my money back.
Still, it's worth a look at their website, to see what they carry.
Prost!