Thank you. Some fascinating stylistic features on that gun, and some good-looking barrels!
I was thinking about the choice of chambering: 6.5x58 S&S. It seems this was introduced in the late 1890s and was going out of fashion by 1937 (https://forum.cartridgecollectors.org/t/6-5-x-58rmm-sauer-attribution/24402/3). This might make the idea of a rebarrel around the latter date seem less likely, although perhaps the owner was on such good terms with the "old" cartridge that they decided to keep it rather than opting for something more "modern".