You will need a better meter. You have any friends with something like a Fluke?
The object is to "confirm" what we 'think' we know. We 'think' we have some idea of what the original Mopar tester had for values, "floating around the internet" but there's nothing like confirming the actual. It might even have marked resistances on the ones inside if they are precision, or at least common color striped resistors.
But to get that meter as accurate as possible, "hard short" the probes together firmly, with the switch in RX1. Adjust the zero set knob (ohm) for the far right "O" on the meter.