"If both are Hydraulic it's just a plumbing thing. No big deal, not withstanding..."

Unless I have read the dates incorrectly, 1952 is being compared with 1962?

There was no hydraulic clutch in 1952.

No need to worry about plumbing. Use the clutch housing from original truck.

And, use the clutch assembly that works with whichever flywheel you need to use (6v or 12v flywheel).

My guess is the 1962 hydraulic clutch housing is not as valuable as a non-hydraulic 54-62 clutch housing. However, a big-truck owner might be interested in a spare hydraulic clutch set-up.