69 coronet R/T non rally dash

Just got my car put back together and fired it up. Had pulled the dash to repaint. Had a number of electrical issues (things not working) most of which I was able to work through with the help of wiring diagrams and a multimeter. Only thing left I can't figure out is the in dash lights. Some work (background lighting, hi beam indicator, map light), but several do not (left and right hand directional indicator light, oil pressure dummy light, and e-brake light). I know for sure the directional lights worked before I pulled things apart. I removed several of the working background lights and plugged them into the directional indicators and they don't work there. Not familiar with how these lights work (assume from looking they get power through the integrated board on the back of the cluster? Since some work I assume that cluster is grounded well? If anyone could give me some novice appropriate troubleshooting tips/instructions I would greatly appreciate it.

Thanks in advance

I've done this tedious task before a few times, and yielded great results!

I screw a wire to a known good ground (even the battery at times) and start touching the the individual bulb holders of the non-working lamps to see if the grounds are bad (after verifying that the lamp itself is working). It takes time and thought, but you'll find all kinds of defects on your old circuit board. Once you know where the problem lies, you can determine how to correct it.

The screws that mount the cluster to the dash are the ground so you need to be sure the paint is cleaned off the mounting hole areas.