What’s the story on these hand-poured .999 silver bars?

From time to time we’re able to dig up interesting pieces of silver, in this case from a local Estate sale. These bars are stamped .999 fine, with acid tests confirming the contents. The bars have a nice heavy feel to them, and have a particularly shiny and flat face (similar to an early Engelhard), contrasted by a very smooth, rounded top/back.

They’re a little bit reminiscent of the early RCM hand-poured bars you see occasionally on eBay going for double melt, but we haven’t been able to dig up any information on them in the almanacs of AG-47.

Does anyone out there in Cyberspace have any information on these bars? Other than the stamp “Liberty”, “5 t. oz” and “.999 silver” there is a small mark on the round side, a square divided in half by a diagonal line — perhaps indicative of recycled metal?

We’ll send a BU Peace Dollar for the first person with any information leading to the confirmation of the history of these bars.