68 Dart Circuit board query

Hi everyone... here's an update to my cluster resto, reinstallation...

So, somehow I got everything in and re-connected (not sure how I connected up the circuit boards / pin connectors without breaking anything, as they are such a tight, tight fit. Maybe I should use some elec grease lube next time!), anyways everything was working as it should, including 1 turn signal indicator light! (better than none as was before!)... however, after about 1 day the light for the speedometer starting fading and has now died completely on me. Does anyone know IF you can possibly reach in behind and unscrew the globe/holder from the circuit board? I've had a look but it seems there's no way you can successfully reach in and unscrew any of the bulb holders insitu? So, rather than face the prospect of pulling it all apart again (Steering Column drop is most annoying), I thought I would ask here first!
On a side note, my fuel gauge has started to work intermittently - one day it does, another day it doesn't, irrespective of fuel level - please see pic attached of my sender, which seems to be self grounding to the tank itself... I've read other threads that say to test the sender simply, I should attach a wire to the connector on the sender (where the gauge wire attaches to) and run that wire I've attached to a ground on the body, then turn on the ignition to see if the gauge reads / goes to full... If someone can advise around this would be great... thanks again:)