I don't know the whereabouts of any but do remember them in the Air
Force MARS stations in the Viet Nam Era. As a communications officer,
one of my additional duties was directing the MARS station. I was told

that USAF originally purchased them for SAC and they never performed up

to the Collins standards, so they were phased out and put to use in the

MARS stations and ROTC. We had a lot of trouble with them there too
and eventually were able to get some KWM2-As.