It's interesting reading the varied reaction to the proposal about
dropping the Ampico price-code digit in listings.

As all collectors of Duo-Art rolls will know, Aeolian themselves made
precisely this change to their numbering system, and you finds rolls
and original catalogues both with and without the final price code
digit.  In the UK they never used the price code anyway.

Therefore there is a precedent for separating out the sequential
numbering system from the price codes!

Charles Davis Smith's Duo-Art catalogue gets round the consistency
problem by putting the price code of those rolls which had it in
brackets after the number.

Julian Dyer