Dave,
If you have 1947 and 1950 Advance-Design trucks the front clips should mount on either frame.
Maybe other people will comment on other differences between 1947 and 1950 1/2 ton truck frames (pickup v panel differences) - mostly would be the body mounts and the fuel tank/neck. Front and rear 1/2 ton brakes/shocks were the same.
Some 1946 trucks were registered in 1947 as 1947 trucks, as Dave alludes to. These trucks were 1946 models but are very often called 1947-1st series (not by GM, however).
Maybe someone else will give an opinion about what would be easier - getting your frame cross members back to "original" or setting up a new frame.
