Is my deceased partners Will valid

My husband died a few years ago, and I found out he'd done a will when he was 19 and joined the army - before we got together. This will was the MOD form 106.

He said he had done a new will more recently, when we found out I was pregnant - because he didn't want his mother getting anything that belonged to me and our daughter. I cannot find that will anywhere.

This is where I need some advice, because I can't seem to find the information online - Is the military will valid?

He never actually served, or finished his training. He was involuntarily discharged because he didn't disclose his poor mental health when he enlisted, so was discharged before completing his training - does this make the will invalid, since he never actually served in the armed forces, and it is a military will.