[morzh]

Ronin

Yeah, do you see that wrap (brown) where the ring goes around?
See if the insulation is reliable and there are no rub-throughs.
This ring and the vertical contact where the wire solders to should be insulated from the chassis reliably.
It should only make contact when you press on the handle.

Well, the worst case you will not connect the wire and will hear some noise while auto-dialing. Not desirable but acceptable.
Notwithstanding the fact that nowadays when the stations are no longer that abundant the auto-dialing is more of a "hey look! it works!" thing rather than a really useful thing.