I've done some searching and found a bit of info.
The International part number, as you listed, 143241R91, is also listed as NSN part# 6685-00-629-5007. This was replaced by a newer number, 6685-00-034-2601.
It is also listed as part# 73945, and the manufacturer was Little Giant Crane and Shovel Inc, and 362T was a Stuart-Warner Corporation number, but I can't find anyone stocking either of them.
These trucks were designed to use parts commonly available off the shelf at the time, which is why you often find parts that also fit the older Fords, Holdens and Land Rovers of the same period. I wouldn't be surprised if there's a Holden part that would replace it and still be available.
Tridon would definitely have a compatible part, but you would need to know the specs of the original to get a cross reference.
It may be worth calling Auto Surplus on Tuesday and give them all the numbers. They have helped me out a few times with hard to find stuff.
Another option is to buy an aftermarket gauge with it's own sender and switch them out. That way you know they are going to work together and be accurate.
Or, if you are going for reliability and safety over originality, get a TM1 Watchdog monitor. I put one in my Discovery 1 and it saved me twice now. The temp sensor is in the highest part of the cooling system, so if you have an air pocket, it sits under the sender unit. For it to register a high temperature, the entire thermostat housing has to heat up as the coolant isn't touching the sender. It also taps into the oil pressure sensor wire and lets you know if you lose oil pressure.
Just had a thought. See if you can get the part number for the actual gauge and search for that. It might mention what vehicles and machinery it's used in and you can then use that to find a sender.
Sorry I can't be much help.
Greg.
