Dash lights blink off and on

[49studebaker]

I am hoping someone may have an idea on this. The lamps on my 1985 chevy gauges seem to have a bad connection. I assume this is common in 20 year old trucks. Usually it's just one lamp on the speedometer gauge and one on my fuel gauge. They come on sometimes so I know they aren't burnt out. I replaced all lamps a few years ago thinking maybe just bad connection from corrosion but it never helped. Do the traces get cracked on the mylar printed circuit thing, or I'm I just not figuring out something? I'm hoping some of you folks have delt with this before and can give me some ideas. Thanks