Thanks guys... blind luck and beer might have had a part in it. :p
was stuck for a minute on securing the gauge from turning or shaking within the cluster. Had a smoke and a drink and as I was playing with the PLX bezel, flipped it upside down and strung it back up the gauge's RS-232 cable. Slammed that on the cluster and it sat in there like a champ. Little plastic tack-welds on the PLX bezel for insurance. Idea in the head was have it secure, but serviceable.
....tempted to pull the trigger on
two wideband jammies, a boost/vacuum thingamabob, and an oil pressure dohicky. Toss them all in the glovebox in a sort-of horizontal mini rack-mount deal and call it a day. Been kinda curious about fueling mixture for some time now.