According to one note I have, those are all UTSD-M (M indicating "Modified"), just as the GTMD for Greece (GT "Modified" Diesel) At a quick look, I don't see any other prefix for MMTT UTSD's. as they were commonly reffered, the "M" was not used, except perhaps on the serial Tag. on 108 prefix.
I do have another note indicating that some of Prefix 050 went to Turkey. If only we had Ledgers for Turkey showing each tractor.