Re broken 78rpm phonorecords...
The problem is that a "broken" (i.e. physically separated into
two (or more) distinct "pieces"...!) 78rpm phonorecord may consist
of two (or often more) segments which CANNOT be reassembled into
an actual physical phonorecord!
A 78rpm phonorecord is a physical object...and when fractured into two
or more segments, is very likely to include fragments of the original
recorded disc which are TOO small to be found pre-break!
Thus, a portion of the surface of the original recording remains...in
fact, MUST remain...unavailable to posterity...!
Steven C. Barr