The thing to remember about these vintage 47-53 trucks is 'more or less'. I decided to change the doors in my 1950 to 1953 push button handled doors (with vent windows). I got the correct doors only to find they are 1/4" longer than the original ones. No chance of them going in the hole without major modification.
5 months and major modification later, the doors fit like they are supposed to. Had to cut a seam in the cab and set the opening in the cab 1/4 inch larger. This was NO easy task. There are two doors! It was amazing the work that needed to be done, but it was still worth it.
There is no reason for the doors to be different sizes. In researching this, turns out that different plants had different dies and equipment that could make things this way. If you purchased the doors and they were made at the same plant as the cab 3 years earlier, they would probably fit.
Long story short, they weren't super exact at the time so be very careful how you proceed. I may have tried a little harder when I bought the doors to ensure I got the doors from the Kansas City Plant rather than the St Louis one. Jim Carter has enough of a selection to easily get doors that fit. So, I always assume ALL parts for our trucks could be this way. Grille parts would be suspect because if the opening for them is a little off, guess who pays? YOU DO. LOL!
Sounds like you are doing it right! I would love to see the plywood forms you used.
