To further this, I've just unearthed an original document envelope for Williams 'Apollo' (1967). It seems almost complete, down to a "Printed Material Check-Off List". In addition to generic information sheets about removing the backglass, adjusting coin chutes, etc, there are the following game-specific sheets listed;
"Adjustment Sheet", giving the location and function of each game adjustment plug/socket or switch.
"Post Adjustment Sheet", a playfield drawing showing rubber ring sizes/location and Lib/Med/Cons adjustable post locations.
"Coil Chart", listing number and location of motors, transformer, meter, solenoid coils, relay coils, and giving details (contact discs, wipers and ratchets) of the game's step units, as well as rubber rings used.
As well, of course, as the schematic.
Teachers Pet probably had much the same documentation supplied.