So, Ken was onto it with cross beam? Where does binding beams come into play?

I was back inside this barn a few days ago. The reductions at the joints were cut with a axe not the adze and across the grain, not with it. (as a side note I picked up a adze such as you mentioned, Will, $3.00 a bit rusty but not bad, it has a 9" long blade and a shallow arch) Again, as a double check I saw no marriage marks. The brace tenons were reduced, I could see how they cut the tenon back, sizing the braces to a consistent number. This is done in some scribe frames where the mortice is cut first, than scribing the next member to the mortice. I could see how this could also be done as square rule. I didn't have a tape with me nor the time for further details. Tim