I ran across a video of a guy installing an Altman EZ latch. I went to the website at Trique mfg and found their latch for the AD trucks is for 47- 51 and 52-54. Must have been some significant changes. I have a spare door from another 48 and I found it is 1/4" shorter in width than the ones on my 48. Might explain why they don't fit although it's hard to imagine why somebody replaced both doors at some point.
The change made between 47-51 and 52-54 had to do with the way the latch attaches to the door with the advent of push button exterior handle and its redesigned latch.