John Phillips said:

> ... If they could be decoded, these numbers probably would tell us
> on what date a roll was made.

Rex Lawson did a lot on this about 20 years ago.  In the UK Universal
Music roll factory there was some spat about roll batches getting out
of manufacturing date order and from about April 1920 almost every
Universal/Aeolian roll cut there had a five-figure number on the back,
usually at the end because rolls were stored inside out to speed up
spooling, of the form 21156, sometimes with the 2 in red.  This
signified 1922, November, batch number.

This was verified from the many "Bulletin" sampler rolls surviving
which give the month pop rolls were made.

Confusion loomed in 1930 and the number became: 30 1187.  This meant
1930, November, batch number.  After Aeolian UK folded and Universal
was bought out in 1932, the dating becomes haphazard but continues on
some issues until the outbreak of war in 1939.

The roll labels also changed, and sometimes you find a classical roll
the label betrays as sold new in 1930 whose paper had been through the
perforator as much as eight years previously.

Dan Wilson, London