I will bet it beats the price I was quoted by an upholstery shop, $10,000.00 complete interior
Whoever gave you that quote is a crook.
There's nothing to a pickup truck interior of this vintage.
I had my '56 Cadillac redone top to bottom for $6000. That included two kinds of leather, one kind of vinyl, original fabric, headliner, wool carpet, paint, etc. and it's about 3 times the size of a truck interior.