Running temps, Australian 409

[John Keighley]

At the end of last week, I took our 410 to Premier Instruments in Canberra who had arranged for the overhaul of the original temperature gauge when the car was restored. The gauge had packed up during reassembly. After it was refurbished, it was reinstalled into the car and it's interesting to note that I am now getting higher temp readings (80-85 and sometimes edging towards 90 on the highway as opposed to 80-85 on the borrowed aftermarket one.
Can anyone please tell me what the correct Ammeter should be in the 409/410? The one I have in the 410 is a Lucas with a +50 to -50 scale rather than a Smiths. I'm wondering if this is original in view of the fact that the people from Premier Instruments are doubtful.
John Keighley.