Interesting, I'll have to check my 48 and my 52, I am reasonably sure the 52 only has two fuses, and I have never inspected the one on the 48...
I don't know for sure about being the same on cars as trucks, but I would guess so, as each vehicle has identical electrical requirements and essentially the same system, would make sense to have the same fuse holder on the firewall.
Grigg