Bob,
Another method to measure resistance for very low ohmic values is to plug a lab supply into the BATT end of the RX and a spare lead into THROT. Solder a 5 Ohm 10W resistor to the lead and set the supply to 5V. The current through the traces will now be approx 1A. Verify the current via the lab PSU. Use a uV meter and measure the voltage drop from either end of the PCB trace. My gut tells me you wil calc less than 10 miliohm. More revealing would be the drop across the std servo leads and extensions....
The RX sees the supply of the batt pack minus the batt lead resistance. It follows that the Batt lead and switch is going to be the biggest factor in voltage drop.
Cheers
Andre