Instrument gremlins.

The dash lights will never be bright enough to see in the day time, even on a cloudy day. T'ain't like these new-fangled LED back-lit ottermobiles....

Speedo is still messed up internally, probably the little spring or the needle pivots; either has to come apart or be replaced. I had one do that and just replaced it. At least you know the speed cable and core are good; you ought to lube the cable core someday soon; moly cam lube is my favorite, but white lithium grease will do.

For the blinkers, do the easy thing and get a new blinker can (blinker relay) first; it shoudl be 2 prong. That would kill both front and rear blinkers. Let me ask an odd but related question: do the back up lights work (aassming you have hooked up the 3 prong connector on the side of the auto trannie or the 2 prong connector on the side if a manual trannie)? Also, does the heater blower work? I ask since the power for the blinkers, the backup lights, radio, and the heater blower all feed from the same fuse in that year.

Do you have a voltmeter or can you borrow one? That will really help.