I recently got a 55 CJ from my grandpa that was sitting in his pasture. I'm not too sure on what model it is but I believe it is a cj3b. It's a little rough but I have gotten it started and running with it's original engine f 134 hurricane. But the restoration has just begun.
Welcome! Looks like you have a very early CJ 5. 1955 was the first year for the civilian version of the M38A1. The difference between the military and the civilian version would be the tailgate and the lack of indent on the passenger side cowl.
It will be a good project to jump into the world of Willys. Keep us up to date on your progress.