Ammeter heating up.........

While working on my 69 road runner I had my hand up under the dash and found the positive post on the ammeter to be hot. I gave it a wiggle and it was loose. So first instinct, tighten it up, which I did. The next day I removed the cluster for other repairs. When I took things apart I found the "cardboard" insulation layer on the inside of the cluster had crumbled and fallen off. Hence why it was loose. Of course when I had tightened up the posts the day before I had actually pulled them both against ground. My suspicion is that this is the cause of many people having issues with this system, due to the fact you wont see it unless you actually pull the cluster out. I've read horror stories of heating up and meltdowns. So I used rubber washers for my replacement. They actually were from a faucet repair kit. They fit well, are firm and I believe will be superior to the original material. I had to thin down the two on the inside as they are thicker than the original cardboard. Just thought I would share this and see if anyone agrees with my hypothesis or thinks I should have done something different.