Appreciate all of the kind words.
I did make one error: the bottom metal is not Burgess' but rather was from a batch that Echols had made for use on his rifles (I can't remember who made them). As for why he didn't use the original 1909 metal, I suspect it was to ensure the correct geometry for the cartridges he intended to use. I've spent some time in his shop when he was doing feed work and he is a big proponent of starting out with the right geometry in the first place rather than trying to adapt something else to work. The trigger bows on these units were also left essentially square so that they could be machined/filed to the desired shape.
