help with early oil/engine temp sensor

[G50911]

i have a 67 911 and my temp gauge isn't working. north hollywood speedo did the restoration and sent me a VDO sender (part#323055) but it doesn't work. my mechanic took a look today and here's what he found. can anyone make sense of this:

"Temp sensor resistance value when hot was 184ohms. Added variable resistor to circuit. Gauge doesn't move until less than 1ohm".

I sent this to Ralph at NHS and waiting to hear back (hopefully tomorrow) but wanted to see if anyone here had this issues or knows how to fix.

TIA