This is very interesting to me. I have resurched this myself. But my "TE37" still has the KE55 dash in it, but I have used a tacho from a Celica and it looks fairly factory. I would love the genuine TE37 dash and gauges.
But it seams the gear you have is from a LHD car, probably from USA or some other LHD country where they use Miles per hour. Where are you? I have decided NOT to buy the LHD TE37 gauges because its all just too wrong for my RHD car. I have all the wiring diagrams for both LHD and RHD TE37 gauges (and TE47 Trueno items etc...)
These gauges and everything have to fit in a KE30/KE35/KE36/TE31/TE37 etc dash. They will not really fit in the latter KE55/KE38 dash without more modification.
One day I will buy all the gauges like you have, but it will have to come from Japan, for RHD and in kmh. And I will fit it in a KE30 dash (which is very hard to find uncracked.)