Holy cow, how did I miss this thread?!
First, welcome to the forum, JP! It's nice to welcome another caster to our ranks.
I have a bunch of Schneider molds, too, a couple of originals in bronze, and then a number of modern reproductions made in zinc alloy by Höhmann in Cassel, and a couple made here in the States and sold by Castings/REB Toys. The originals still make the best, crispest castings, as do Höhmann's molds.
Regarding your mold with the "S and arrow" marking on it, if I'm not mistaken, it's not actually from Schneider Bros., but was made here in the States by a gentleman named Henry Schiercke. He was a German immigrant (I believe) around the turn of the last century, living in New York, and he sold toy soldiers, and eventually, homecasting molds, including Schneider molds. At some point, he commissioned copies of the original Schneider molds and sold them under his own label. In fact, some collectors group the originals and the Schiercke molds together as "Schneider-Schiercke" molds. Though Schiercke's were copies, there was no loss of quality, and they were much better, in my opinion, than the generation of home-grown American molds that they inspired. (This is from memory, from Ed Poole's article on homecasting, in Richard O'Brien's "Collecting Toy Soldiers".)
The series made and sold by Castings are copies of copies, and they're not designed as well as the Schneider and Schiercke molds. They're too big, so it takes longer for them to warm up. Also, the figure is centered in the molds, rather than to have the open bottom of the mold form the base. I've found in casting with those that it takes more passes till the molds heat up and the metal fills the cavity, and the way the base is formed, with a key in one side fitting into the other, is clumsier to use. But here is the URL for the page in Castings' catalog for their version of these old figures:
http://www.miniaturemolds.com/ser05__.htm, so you can see a full series of the figures.
I still have a catalog from Höhmann, though I haven't ordered anything from him in over ten years. He used the original Schneider designations, as far as I know.
I have to fire up the pots and do some more casting, it's been a while. I have some castings from the last session, too, that I have to paint. These figures were the ones that drew me into the hobby. I bought a set when I was a student in Munich, and later learned about the origins of the molds. I found one at a flea market, and then found commercial sources for them, and also rubber molds, and then I branched into kits and castings of fully-round figures as well.
Well, I've run on quite a bit. Please do show us more of your work as you go, and if you have any questions about casting, please just ask!
Prost!
Brad