Q. David Bowers book, "Encyclopedia Of Automatic Musical Instruments,"
lists and illustrates on page 180 four styles of Regina that use the
8-1/2" disc: styles 21, 22, 23, and 91.  The 8-1/2" was the smallest
Regina disc.

If you haven't read pages 170 to 212 of Bowers, you haven't really
dug into Regina in any serious way.

Matthew Caulfield (Irondequoit, N.Y.)