HP-65: uneven feel of the keys

[vaklaff]

I obtained a 65 in a not that bad visual shape. Of course the card reader didn't work but the display and electronics seemed to work fine, the batt compartment was on the cleaner side, just the keyboard wasn't very reliable - some keys needed effort to register, some were prone to bouncing.

A few days ago I disassembled and cleaned the calculator. I saw no corrosion nor mechanical defects on the keyboard contacts. I gave them a good splash with IPA while softly clicking the domes with a pencil eraser.

Now the keyboard action is much better. All the keys register fine and I don't see much of bouncing, if any at all. Yet I am not completely satisfied. The feel of the keys is uneven, some are softer or mushier and even look a bit sunken. I can live with that, after all the calculator isn't a work tool, it's a toy (just don't tell anyone ;-). However I'd like to ask, is there a simple cure for the uneven keyboard?

Thanks in advance!