Jaguar XJ gauges in my GMC

[c10hevy]

I snagged these gauges for 96 bucks along with the mounting bracket (less than a single autometer) and welded in the bracket today, what do you guys

Its even got a 6 cyl label on the tach and I have a 250, Thought that was pretty cool

does anyone know what each wire is on the round stock connector? Ive got the jag side figured out but not on the gmc side any help would be great so i can get these things hooked up and working

I was thinking about cutting out the center of my stock cluster and sandwiching it between the metal bracket and a faceplate that i have yet to make. any advice/ideas on making up the difference between the gauge face and the bracket?