Yes. This is correct. Button Disabler version 1.1 was the last version of the control panel released by Apple as part of System Software 7.5. The Power Macintosh 5200/75, 5260/100 and 5300/100 computers shipped with a System Software 7.5 based installer. This installer for these computers was created from System Software 7.5. This computer specific installer allows users to custom install the Button Disabler control panel v1.1. The Power Macintosh 5260/120*, 5400/120 and 5400/180 computers currently ship with a System Software 7.5.3 based installer which does not include the Button Disabler control panel.
Note: The Power Macintosh 5260/120 does not ship with the Button Disabler control panel. However, since the Power Macintosh 5260 logic board is based on the Power Macintosh 5200/5300 logic board, the control panel should install and work correctly.
Button Disabler 1.2
This control panel lets you disable the bezel buttons on the front of certain computer models. If you have a Performa or Power Macintosh 52xx, 53xx, 62xx, 63xx, 5400, 6400, 5500, or 6500 series computer you may use this control panel while running Mac OS 7.6.1 or later. Version 1.2 of the control panel does not support any Quadra or LC series computers or computers with a PowerPC upgrade card. Continue to use the version 1.1 of the Button Disabler with those Quadra and LC series computers.
These articles can help you locate Button Disabler 1.2:
This article was published in "Information Alley" on .12 Sep 1997