I was reading something about the large amount of .45 ACP ammunition (335 Million rounds) made during WWI in the US. There was mention made of two ammunition manufacturers, namely Maxim Munitions Corp. and Pan American Munitions Corp. that also made .45 ACP but these two did not produce much. I note that there is a previous posting about Maxim Munitions, but it provides little information, and in any event was not related to .45 ACP production. I saw nothing about Pan American Munitions Corp in the postings.
I would think any existing .45 ACP examples (and boxes, ephemera, etc.) from these two would be rare if not extinct. Does anyone have further information about these two manufacturers?