- not sure how to test the PTO switch or seat switch.
- likewise with the brake switch.
Congratulations on freeing the mower !
A very high percentage of the weight is placed on the drive wheels, so you've REALLY got to watch what the ground under them is like. Anything approaching
moist is typically a no-no. Watch yourself around lakes and ponds. Just because it's firm enough to stand on to fish, does not mean it will support a mower.
On the switches... it depends on how the safety interlock system is wired. Some switches "make" the circuit, while others "break" the circuit. However, they all test the same way. Using the Ohm scale on a VOM, unplug the switch wiring, place the meter probes on the 2 switch terminals, then activate the switch. The meter should indicate "All & None" as the switch is repeatedly activated and released. Test the seat switch first, they seem to go out faster. (Something to do with BBQ and peach cobbler.)
And whatever you do about a bad Seat Switch...
don't tell the wife. She'll simply say it's proof you need to loose weight !