Hello!  Tom Hawthorn wrote: "Along with these rolls are a number of
QRS rolls that are only 10-1/2" wide ... wooden spool ends and a 1/4"
square drive hole on the right side."

I think they're 58-note piano/organ rolls having the same spacing as
the standard 65-note piano rolls (the scale of which actually is an
extension of the 58-note scale, though not sharing the paper width and
drive holes).

Christofer Noering
Stockholm, Sweden