Piping in here, looking at the discussion, and comparing pictures of pre- Z GMC and pre-54 AD dashes, including my ‘54 450,
It really looks like a GMC Z instrument panel grafted onto a , presumably 53 dash!
Frankenstein? If so, ain’t we smart to figure it out!

~Charley
1954 Chevy 3100 with 235
“Bud”
Follow along in the DITY
1963 Chevy half ton stepside short box 230
1954 GMC 3 ton 302
And several more Chevy camper and work trucks 1979 1987 1996