(Z)691-1231-A is the machine-specific Install CD for the 7300, 8600 and 9600, all of which terminated just before, on the day or a few months after the day on which the beige G3 was released with OS 8.0. It installs System 7.5.5.
However, the extended PB 1400, at least, shipped with OS 7.6.1.
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