Holy hell, really? The USN mounted predecessors to the Mk 32 SVTT as early as 1944 on a limited basis, and the direct predecessor to the Mk 46 went into service in 1950.
just checked, and the RN has not fielded any short TT's in any ship, apart from the Mk 32 SVTT, apart from some testing. the Dutch at the time followed British design practise, so it is not weird we did not fit these until we started looking at US equipment (Tartar). the british did also fit Mk 32 SVTT around the same time, in 1974 on the type 21 frigate, to be exact.