I missed this the first time around. Thanks for the great and detailed write up. I had one of those barrels and the first beer I put in it was a normal gravity stout and it sucked up the bourbon flavor very quickly (like 5 days). It good, but a bit overpowering on the bourbon. The second batch I put in was a porter that I left longer that turned out great. Then I neglected the barrel and it's dried out now and probably toast
Fun experiment and thankfully I got a bulk discount price on the barrel so it didn't cost *too* much per batch.
On the original bottles that never carbed. Any thought to carefully pouring them (to avoid oxidation) into a container and adding some yeast and then bottling again? Wouldn't that help them carb up?