Those are tough to align and often the graphite ring or the pin has seen better days. Replacements are down to used parts that may not be much better.

Although I managed to keep the ones I had working, it is down to upgrading to the newer style if you want it to be more trouble free.

On a Paratrooper I restored several years ago, I converted it over to the modern parts.

Modern parts being what they started using in the 1950s. lol.

Graphite is pourus and soft... and provides it's own lube. I'd say there is defiantly value in moving to modern parts.
That said; I don't have any experience with EMs much less of this era.

What would happen is the wire post sticking down from the bumper skirt will get loose and it and the graphite ring will get burnt in spots especially if the skirt sticks. It is a tiny ring hanging by a wire screwed onto the bottom of the playfield with a wire soldered right onto it. And another wire soldered to the skirt pin.

It was basically a prototype of the modern unit and could work for decades, but since there are no replacements available, you gotta do what you gotta do.

One other option if the skirt pin is still good is to remove the graphite ring altogether, which sometimes happens on it's own, and bend the remaining metal ring a little smaller. I've done that on a few and am yet to actually upgrade any to the newer system.

As far as the conversion, it would probably just take a new skirt and switch assembly and spoon.

I wrote this up in Gameroom Magazine ages ago but you can replace the graphite donuts with a brass ring. Here's the thumbnail summary:
Donut composite (resized).jpg
I drilled out some brass knurled nuts and soldered them in to the steel wire holder in place of the graphine donuts. The brass is still softer than the steel post so it shouldn't wear it down. It worked like a champ while I had the game anyway. You could probably make something out of brass sheet stock too. It wouldn't snap into place like the knurled nuts, but it should work just fine once soldered in.

/Mark

This is what I’ve done. Works just fine.

I carry the Carbon Contact Rings on flippers.com:

https://flippers.com/catalog_oc/carbon-contact-ring-5022?search=5022
John:-#)#

5022-CarbonContactRing (resized).jpeg