Interesting - if you go and look at the original ebay listing posted in the OP, magnify and look closely at the last picture of the bell it looks like the horn is engraved 14M.https://forum.saxontheweb.net/showthread.php?48844-Conn-Baritone-w-Rolled-Tone-Holes
There it is! Thanks SOTW!
If it goes for under $1g it is a good price regardless of whether it is 12M-ish or not, actually. These were quite decent, UMI put some thought into their upper-shelf models....Horn looks like it's in okay shape (hard to tell since the pics are not great) and the seller claims it's recently been serviced. Seems like a really good price for Conn bari if it's basically the same body tube as the 12M.