Hi Chris,
I don't think the piano is dreadfully out of tune in these recordings. One of the other members here and I recently did a test, as for one of my new recordings the piano's high treble was supposedly "out of tune". I then recorded a slow ascending scale from middle C up to the top C. We reviewed every tone carefully, and aside from a very few slightly off unisons, the entire treble sounded very well in tune. Clearly the perception is some sort of inharmonicities phenomenon resulting from the mixing of overtones during the playing. Baldwin stops the dampering of strings lower on the treble scale than does Steinway, so there are fewer dampered strings in the treble. That might be the difference. To my ears, I don't even notice it to be honest. A technician at Piano Tuners and Technicians on another forum thinks it might also be that listeners believe that higher treble notes sound "flat" to them, so they must be "out of tune". The fact is they are tuned at A440 like the rest of the strings. To satisfy those listeners, you'd have to tune those notes sharper than the lower octaves to make them sound "normal". And in this hostile northern climate, I do keep the Baldwin at sharper concert pitch during cold weather and then lower it to A440 in warm weather, tuning at an interval of every three months. And I try to make most recordings immediately after tuning. I can't do much more.
As for these older analog recordings, you have to consider a tiny degree of tape speed variation too from electric/mechanical fluctuations in a tape deck.
During the evolution of sound recording, 78s were compared to cylinders, LPs were compared to 78s, and CDs were compared to LPs and tapes. Undoubtedly some new technology will arrive which will look back at CDs quite unfavorably. And we'll all be saying, "Well, those CDs sure sounded great at the time!"
David