I ran across this Seeburg 1000 Background Music System at an antique store in Lexington, KY. I’d never seen one before. The price was $1200, so I passed on it . The system used proprietary records provided by Seeburg, and the machine could play both sides of each record. Up to 28 records could be stacked in the unit. Records were changed four times a year. The records were 9� with a 2� center hole, and played at 16 rpm. More information can be found here:

https://en.m.wikipedia.org/wiki/Seeburg_1000

I no longer look at vintage radio equipment or record players with highly inflated prices in antique stores. I used to (politely) educate them, but they just looked at me as if I had two heads...
Fools… I don't know who buys this stuff. lol

Some eBay.co.uk internal photos.
https://www.ebay.co.uk/itm/334444421724

The proprietary records with only Muzak available is a deal killer for me, I'll stick to regular Jukeboxes.

Mat over at Techmoan has done a great couple of videos (1 | 2) on these machines, along with a host of other BGM players. They're a neat alternative to owning a jukebox in your home, I think. (Not necessarily cheaper, though)

I bought a Seeburg Library unit, model 200 for 80 dollars at a record swap, as is, not working. After a thorough degreasing and replacing all the caps in the preamp, it's working pretty good now. Takes a hundred standard 45 record and each record has a switch to select side a or side b or skip it. Designed to play continuously all day until turned off. Bad thing about it, it takes special pickering stylus and the two in my unit were worn down to the stubs, had to shell out 140 bucks for a pair.