Engine size..?????
I would do absolutely NOTHING else until the cause of Low compression is pinpointed......
From experience, Temp gauges DO NOT read correctly unless they are IMMERSED in coolant...which means you could have Overheated it and not even Known about it ....(Stuck T-stat or a coolant leak that you havent noticed until it emptied out) .......Which could easily lead to head gasket failure if left unattended.
Passenger side of the car, on the Timing belt cover is a round plastic plug, about 1 " in diameter...Pop it out, and you will see the timing gears thru the hole. Have an assistant crank the engine while you observe the gears thru the hole....Do they turn????
A stuck T-Stat, in no way shape or form will stop a car from starting, but the end result will.....