. . . original trucks that have been in wrecking yards . . 
Those "original" trucks are not on the road - so, this is proof of what? Almost none of "those" original trucks had their filters installed at the factory. I worked for a dealer in the late 60s - need I tell you have many times (never) I saw anyone look at a manual or at an installation sheet?
Those mis-installed oil filters might have worked, yet they might not have worked and that would not have caused any short-term noticeable problems (perhaps no worse than not have a by-pass filter at all).
There is nothing like documentation for a correct installation.