I'm afraid you wouldn't be able to sell these as heirlooms, because they're not worth too much. Your dad's figures are referred to as homecasts, because they were made from molds that were made for hobbyists to cast their own figures. These come from molds originally produced by a German firm, Schneider Bros., and possibly some from another German company called Ideal (pronounced "ee-day-all"). The molds were first made in the 1890s and were produced in Germany up to the end of the Second World War, but they were also copied by small companies here in the US, particularly in the Twenties and Thirties. There are also some mold makers in Germany who still produce copies of these molds. It makes it very difficult to date the figures. Also, since these were used overwhelmingly by hobbyists, the quality of the metal used, of the castings themselves and of the painted finish, varies wildly from one figure or group of figures to the next.
There are collectors who do collect homecasts, but they're a narrow subset of the broader world of toy soldier collectors. I have some, but I have the molds to cast the ones I have (both original molds in bronze and newer copies in a zinc alloy). Some collectors find a charm in the toy-like design of the figures, and appreciate these figures for their place in the evolution of the toy soldier and model figure.
I recommend taking a look at contemporary auctions, starting with eBay, to get an idea of how to price them, but for myself, I think a dollar apiece is a reasonable opening bid.
Hope that helps, prosit!
Brad
