Don,
I really like the idea of the blocks lifting out of the box to be used as loading blocks on the bench. Once the cartridges are all (50) loaded they will just be set back into the box and then just repeat with the second block to end up with 100 round for a match. That is usually enough to shot a weekend match at Lodi or Alma, about as far as I travel these days.
I can use the MTM plastic boxes I just got to carry as many extra rounds as I might need. They work well but with the bullet down. I would just use these to replenish the wooden box each day before the match. That's my thinking anyway.
If I decide to make another box out some better wood I would make a few small adjustments in the size but what I have will work well.
I made the holes .640" diameter and the Jamison brass fits very well so the BACO brass will easily fit with it's slightly smaller rim diameter.
I'll put some stain on the box tomorrow after filling some of the bigger old dents and sanding it some. In the end I think it will look good enough and function well, though it certainly won't win any beauty contests, but you have consider the guy carrying it! That is the main reason I shoot paper patch bullets, they always make me look better!

Which is asking a lot of my bullets I know!