@joyRidaz, thank you for the compliment, Im glad it was helpful!!
1. My opening is 41 1/2 inches fender to fender. To keep my gaps spaced "equally" I tacked my doors to a piece of 1/2 inch angle iron. I made sure I centered my latch when I tacked it. Then I used those wooden shims to keep it centered in the opening.
2. My backing plates are 14 ga and I had some pieces bent at our shop at work. i had been wondering how I was going to get some metal bent and during my research, I found a bunch of places around town to buy the metal and bend it. But I decided to use the shop at work instead, because they are "free".
3. Funny you should ask, I was fixing to post up some questions about the barrel latch dimensions and pictures. I think it is going to have to be fabricated. I have never seen one so I don't know. I going to use it because the doors need it for support IMHO.