Thanks again for the continued responses.
Still haven't opened it back up, but had another malfunction today: it rang, and I picked it up. Completely dead. Left it off-hook, and ran into another room to pick up another phone on the same line. By that time, the calling party had disconnected. When I returned, I had dial tone in the problem phone.
That almost sounds like something's being slowed mechanically -- like some sort of viscous dampening -- and delaying the hookswitch contacts from making. That might also explain the static: if something is becoming mechanically sluggish, then the "initial static that eventually clears up" might be from the mechanical problem causing a "loose" make, that improves over time, and the "intermittent dead that goes away by the time I try to do anything about it" might be from the mechanical problem delaying the make completely.
Does any of that sound at all sensible? Or am I sucking antimatter?
To Touch Tone Tommy: How would I tell if it's drawing dialtone, but not audibly? And as to cleaning the contacts, the first thing I tried was 91% isopropanol, mostly applied to various kinds of paper and pulled between the contacts. I think I used to have a contact burnisher of some sort, but I have no idea where it went, or even if it's the right kind (and would not want to use anything too coarse!)
