ASA 125 Tungsten sounds like VNF, an old film used for news shows. I don't know whether it was produced in 35mm, but I don't know of any other 125 ASA Ektachrome film. If it is, it requires VNF processing, which is different than E-6, although I don't know how different.
I've an empty carton for a roll of 35mm "High Speed Ektachrome Type B" for tungsten, expiry early 1970's, and 125 ASA. It was labelled for the older E-4 process.