The Factory Assembly Manual seems to use drawings from '54/'55-1st trucks. The '54/55-1st frames had changes in a few places, in comparison to earlier Advance Design frames.

Maybe someone who has frame information for 1952 and 1954 can comment on whether the frame changes that took place in '54 are significant (with respect to using the '54 measurements for '52 repairs). I do not know enough about the differences to answer this.

Tim