Can you tell me anything about this rear loaded horn I bought?

[Doug_Dornbos]

Can anyone tell me anything about this rear loaded horn I bought on eBay? The seller didn't know much about it. I paid very little for it.
(I am attaching a picture as a file.) It has cutouts for both a 12" and a 15" speaker side by side firing down into the scoop. Each speaker has it's own chamber which loads into a common horn throat.

I put a plumb bob through the horn and it measured 43" long. The throat starts at approx. 2" in height and is the full width of the box. The divider between the 12" side and the 15" side only extends 4" into the throat and then it ends.

Do you recognize this horn? was it a design that came from somewhere like a magazine article or something like that or would you guess that it was just a single hobbyist creation?

any input would be appreciated as well as advice on what to do with it. my original intention was to use it as a bass guitar speaker cabinet.

thanks
Doug