1947 truck fuse box (a little better than the one shown below)

1948-1952 truck fuse box (not a very good picture)

No matter what the Shop Manuals show above, The Master Parts Manual shows different boxes for 47-49 and 50-54/55

It looks like:
47-49 had 10 terminals (five fuses, as shown above)
50-55 had 4 terminals (two fuses - sorry, I cannot find a photo)