it is toasted, get a new coil and sleeve and you should be back in business

What Boilerman said. Replace it.

It is probably shorted internally, instead of disipating the current draw, which is why it blows the fuse.

Be ready to track down the reason it stuck on. This did not just happen by chance. There will be a switch stuck somewhere that kept this energized which caused it to burn up.

The Right and Left pop bumpers are both controlled by the D relay, however by separate switches on D.

D is activated if either the Right or Left pop bumper spoon switches closes.

Once activated, D remains locked on until both EOS switches on the Right and Left pop bumpers open (so they both need to fire when D activates).

So if one of the switch contacts on D doesn't cause one of the pop bumpers to fire, then:
- D gets stuck on,
- the 'other' pop bumper gets stuck on,
- the pop bumper coil overheats,
- the plastic sleeve melts,
- the plunger gets wedged in the coil and can't release

which probably contributes to the fuse blowing.

After replacing the coil and sleeve, make sure that both pop bumpers are activating and opening their EOS switches, so that D doesn't get stuck on.

Correct

I can't quite tell from the picture which one is left or right (too close in, no reference point).

Correct. D is a relay, not a solenoid.

(Incidentally, on Gottlieb schematics, relay coils are depicted with the 'loops' hanging down and solenoid coils are depicted with the loops pointing up.)

The pop bumper relay is activated by the spoon switch closing, and when the EOS switch opens, the bumper should release.

I think it's entirely possible the skirt got outside the spoon switch and caused the bumper to lock on. I have had that happen. It's interesting that the other bumper didn't burn up.

That's cool; I didn't know.

Wow you learn something new everyday.

That's the coil stop stuck inside the old sleeve. Since the old coil heated up, the sleeve contracted around the coil stop and probably the plunger. (The coil stop is the piece with the threaded end sticking out.) The coil stop should be attached to the coil bracket, and normally doesn't get stuck inside the sleeve.

The chipped part is just the plastic lip on the sleeve.

You'll probably need to get the coil stop out first, and then tap out the plunger from the newly opened end (once the coil stop is out of the way).

screw it back to the bracket then knock of the coil that way you don't damage the stop threads

Or put the nut back on it and grab that.

Two pieces as shown.

Your thumb and fore finger are holding the coil stop.

The rest is the plunger mechanism - the working parts.

Get a new coil and put it back together and then see what caused it to stick on and fix that.

If you really are unclear, disassemble the bottom side of the other pop bumper to see how it is set up.

The rollover could just be a simple contact clean and adjust. With the hood up, try lightly contacting the relay to see if it engages a score. If it does, lightly press down the playfield rollover to see if it contacts the relay and gently bend/adjust until the two contacts make contact when the rollover is engaged. If it registers nothing, trace the wires and check for a bad solder contact, loose wire, or wire crack. If nothing there, check the ohms running through the coil that powers that relay to see if the coil is fried.