There is usually the
Shop Manual and the shop manual supplements for years following. In your case, the '46 manual is probably the supplement and there is a older manual with more information in it.
owner's manual(which, the older the vehicle, the more information there is in there)
Some models have the 'accessory installation manuals' which go across all models of cars and trucks for that year, don't know if they had one for 1946 or not.
check out the links section, go to parts and look in the manuals/literature sections.
American Classic and Classic Parts of America both have pretty thorough literature sections for our old trucks.
-W
