HMV Internal Conduit type from another maker?

[HMVDevotee]

Here is one odd machine. Any idea who made it? I don't recognize the components, especially the horn's long throat that fits in a trap door! Doesn't look like any of these pictured below.

https://bellingham.craigslist.org/atq/d ... 89441.html

[Steve]

Home made. Nothing to do with HMV whatsoever.

[JeffR1]

If the seller gives me 80.00 bucks, I'll take it off his hands and take it to the recycle bin.