Posted 4 years ago
Most keysets were supplied with clear buttons, and usually a red button for the hold feature (if present). Pressing the hold button released the latching keys. Other colored buttons were occasionally used to indicate special features or to help some lines stand out for ease of use.
Here are a few loose buttons sent by Rick Gast and from parts boxes at shows.
The set is a 2568 HAAM, 3/79.
The 2 clear buttons on the set are on latching keys for seperate lines, and the three colored keys on the right are on momentary keys for signaling. Most phones had one momentary contact signal button - typically to buzz a secretary, receptionist or members of a work group when calls needed to be transferred or a latching button for internal communication (intercom). Multiple buttons could be used for selectively signalling different individuals or groups.
The larger loose keys on the right came from later model Call Directors or sets such as the 830, 831, 851 or 852.
For more on keysets, see the chart here: http://www.paul-f.com/we500typ.htm#Key_Sets