The problem I have found with 555 sockets in the bumpers is many of the older bumper bodies are too short (or the 555 bulb and socket are too tall) to fit in there properly, particularly when using the wire leads. I have gone back to using the strip metal leads with a stapler.

Yup, they are a pain in the butt.

Some people will solder a piece of wire to the lamp leads and crimp electrical quick disconnects on the wires. Makes it easier the next time you have to pull them.

You guys really have a lot of pop bumper problems if you have to put quick disconnects on them....just sayin'.

I just leave the metal leads loose, solder the wires on, use a short hex head screw with a washer to secure the lead to the playfield, then reinstall the coil assembly. This has made it easy on my games but may not work as well on some games that are more congested.

Lol, nah. It just makes it easier to put them back together. And for the next guy in 2035 that wants to tear down the playfield.

LOL. It really doesn't matter as far as lighting goes, quick connects are fine if that is your thing. To me that's just another problem waiting to happen. A good mechanical connection covered by a thorough electrical connection (soldered) is a reliable connection where I don't have to worry about my pop lamps going out in the future.

Don't have to be good when you're just doing 2 pieces of flat metal under the PF.

Chris-
Try this: tin both the socket blade and wire end with fresh solder. Then, use a small tool like a screwdriver blade to hold the wire on top of the blade. Heat with iron until both are liquid. Wait to cool and remove screwdriver holder. Works pretty well for me. If you staple them down first, even easier.