I bought a gauge, found a helper, disconnected everything you recommended, took the readings.... but forgot to wire the throttle back to the wide open position before checking the cylinders and didn't notice until my helper was gone.
These numbers are probably inconclusive without doing that, but here they are anyway. Maybe you can glean some information from these.
I'll do it again when I can get my helper back tomorrow.
#1 140
#2 150
#3 135
#4 135
#5 140
#6 147
#7 145
#8 140

I'm going to go out and pull the valve covers off now and see if I can see anything that looks out of sync.