Mission 765 Problems

I have a pair of Mission 765's that I love. However, they have started to give me problems recently. Sometimes my sound partially cuts out in one speaker. I had them connected to one terminal and the plates connected both terminals together. I thought that might be culprit, since sometimes I could push on a plate in between terminals and the sound would magically come back in full. So I removed the plates, and I ran two sets of wires to each speaker, with one wire connected to each terminal.

The problem seemed to have went away, except now it has been doing it again. I noticed that when I push a speaker terminal in, it will stop, then continue based on my pressure. I took the crossover in one speaker out, and tightened the terminal nuts on the back side. That seems to have helped one speaker, but now my other speaker is doing it.

How should I go about repairing this? I am capable of using a soldering gun, heatsink and minor repairs. However, I don't know where to look for what parts might be bad, what connection might be old, etc. Where do I begin troubleshooting my speakers?

Thanks for any and all help!
Since you can duplicate and resolve the symptom by putting pressure on the speaker terminal I would have to say there is a good starting point. I would start by tightening all connections and re-soldering (if soldered)any connection to the speaker terminal.

Those speakers have got to be on the order of 20 years old (I have the mission/cyrus 782's although not currently in use). My speaker terminals on the 782's have a nut that holds a soldered wire to a round lug.