I think the original (but "final" design for the next 40 ++ years) La Scala had sensitivity identical to the Klipschorn, if measured 400 Hz to 3,000 Hz, which was 101 dB, 2.83v, 1M, and a bit higher in the "typical" listening room.
I'd agree, La Scalas and Belle Klipsches roll off at about 50...