Mastertouch Recordo rolls had a unique prefix of E.  Some rolls prefixed
C. and D. were later issued with expression coding, but with the prefix
changed to E.  It should thus be easy to identify those rolls without
unrolling or punching them.

The coding was the 5-step, or "B" system, and was not inspiring.

Bob Billings
toadhall@sprynet.com