I was not getting brake lights consistently on both tail lights. I thought the easiest way to fix it would be to hook up separate brake lights and run a new wire.
I found a set of taillights from that vintage, painted the bodies and put them on next to the other tailights. The plan is to use the existing lights for tail and turns and the new lights solely for brake lights. I am using the new lights as backup lights also since the PO had a huge ugly headlight that is used when a pickup has a snow plow attached.
Before:

Here are pics of my new brakelights:
this pic, no lights turned on:

this pic just tail lights:

this pic with tails and brakes:

I had all lights working: tails, turns, 4-ways, and brakes, except the left rear tail light did not come on. The 4 way and turn worked on the left, however. So I took the tail light wire coming out of the lamp body and spliced it into the wire that goes to the clearance lights and it worked! Later I checked the 4-ways and turns again and.... the left turn and 4-way did not flash...Ugh... so i will try to figure something out tomorrow! But at least I have brake lights. The new lights also provide the backup lights.