Cross Hallmark on Vintage Silver Rhodium Brooch

[Peganmn]

I picked this up awhile back. Initially I didn't think it was marked but then I noticed a cross in one corner that is not in the other corner and it doesn't follow the line of the brooch. I'm fairly sure it's a deliberate mark of some kind, but I haven't found it anywhere. It doesn't really look like crossed swords as I ran across that mark. I'm assuming this is an American brooch, it acid tests as sterling, and the front looks to be Rhodium plated. It is light weight, but very nicely constructed with a pretty Art Deco flow to the design. Any help figuring out who the maker is would be appreciated it