it's bally part C-342A - "guide ring"

they rarely have a problem unless someone sprayed something in the coil sleeve, the coil overheated and melted it, or a metal sleeve wore through and there's a sharp edge inside shaving the ring away.

take a look at the sleeve, you may need a new one - if you can get yours out. If not, you'll need another coil.

anyone with a parts machine should have lots of the guide rings ... or you can get them new for a couple bucks.

if you haven't sourced pieces yet, see if you need the ring or coil+ring and I'll see what I have.

solenoid coils ... the ones with plungers ... should never stay powered for a long time. They are high power and will get red hot if left powered. Whether something catches fire before the coil wire melts apart or a fuse blows is a crapshoot.

don't just replace the pieces without fixing the problem, or you'll be rolling the dice again

which unit cooked the coil ... magic screen feature unit?