There is another discussion about different Sawtooths: https://68kmla.org/forums/index.php?/topic/5527-macos-86-on-sawtooth-g4/
You can ask "Apple System Profiler" when running MacOS 9, you can open the Mac and identify the number of the mainboard, you can compare the power connector here: http://www.outofspec.com/frankenmac/wire.shtml, look for a heat sink on the ethernet chip (-> Gigabit), ...
But you cannot clearly identify a Sawtooth by the model number written on the back side.
HTH, Ralf