Note
CQ, May 1955, page 68.
Walter Ashe catalog 1957 (probably issued in 1956), p. 12.
Allied Radio catalog 1959 (issued 1958), p. 384.
Allied Radio catalog 1960 (copyright 1959), p. 403.
Allied Radio catalog 1961 (copyright 1960), p. 397.
The difference between the "A" and "C" versions appears to be the type of microphone connector used, as both early and later versions have been found with three different styles of connectors.
The 584-C was specifically designed for use with the Collins KWS-1, 75A-4, KWM-1, 32S-1, and 75S-1 (Allied Radio catalog 1959 (issued 1958), p. 384.)
As the manual does not show or describe the connector in detail, and since users could easily modify the patch with any type of connector they found most useful, it is hard to know exactly which connector goes with which type.
Matches the 583 Q multiplier.