Thanks for the closeup, doesn’t look quite like I expected. The etched lines look quite wide and shallow, but the design of the half moon infill pattern does look similar to the St Louis version. Maybe St Louis was the inspiration for that aspect.
Yes there’s probably a lot of old uranium about in people’s houses (I wouldn’t be surprised if your house showed up on some sort of government detector

)...although I would be more concerned by asbestos!