Looking through the archives, it seems the sensor is a 3/8" NPT type sender.
According to CruzPro the following types work with the T60:
U-1: VDO Type 1 temperature sender (10-180 ohm, 92-276 deg F)
U-2: VDO Type 2 temperature sender (10-180 ohm, 45 deg C to 155 deg C)
U-3: VDO Type 5 temperature sender (10-180 ohm, 93 deg F to 272 deg F)
U-3: VDO Type 320.720 temp. sender (10-180 ohm, 93 deg F to 272 deg F)
U-4: Teleflex 10-180 ohm sender, 117 deg F to 294 deg F, 47 deg C to 145 deg C)"
U-5: Cyberdyne 1000-75 ohm sender to 70 deg F to 260 deg F
Now if anyone has a particular recommendation, I will be set to go.