You've got the original 78s John?
Yes, the US Victor opera records I collected while living in Ohio late 1980s. The few 1907 discs I have were likely found in junk shops and antique fairs there, and I remember one anteeky shoppe in Berea, Cleveland where I bought about 50 Victrola records from 1920s (many were re-issues of pre 1920 recordings) a lot of Caruso Chaliapin, Farrar, Martinelli, Sembrich etc. Their sound is a lot better than the 1907 discs which are a bit swishy. No great value to any of these discs, there are thousands of them still about.
I expect the discs in Paris asbestos are on the label
La Voix De Son Maitre the French equivalent of
His Master's Voice here, though maybe
Gramophone Concert, coincidently I posted a copy of one of those labels to Ollie at the weekend
Ollie, I'm not hot on Aussie accents, though I do watch
Home and Away occasionally
I just got the swishy 78 onto my deck here with stylus etc and I don't regard the voice as impressive, it would sound better on a gramophone but mine are at the moment sat at the back of the freezing garage right now.
I'm sure there are accounts of how her recorded voice compares to the stage. Back in 1907 the process was still very primitive, she would be crammed quite close to the small orchestra yelling into a horn.