I like Big Bertha! Wish I could see more of her (the insulation jacket--while practical--hides most of her. But then I suppose she might be modest.)
As I mentioned above, we had some sort of radiator system in one house, and my mother talked about how comfortable that house was until the end of her life. My mother did not like cold in the least, so she was a bit of a connoisseur of heating systems. (Although she was practically minded. She wouldn't have sat, glued to a computer monitor, watching, say, videos of old furnaces. That's what her crazy son might do, naming no names...)
As for the temperature rise of 5 degrees above the thermostat setting--it seems like a bit of playing should get the temperature where you want it. One aspect: when the boiler isn't running, there is probably a lot of residual heat in the system that will continue heating the house. Point #2: the thermostat may have calibration issues. I have a far newer thermostat, and it's 5 degrees off. You can probably learn to adjust. (Unless the thermostat becomes a problem, I wouldn't replace. A digital thermostat would seem just plain wrong in that house!)
By the way, is the house a true "Craftsman" (Gustav Stickley) or just from that era? My mother absolutely loved Stickley design...if she'd had the money, she'd have had one of his houses, fully furnished with his furniture.