That's a good question. The military often, one hand doesn't know what the other is doing. Near the end of 1979 i saw one of the NIB TCS sets being given away by Navy MARS at Sand Point NAS Seattle, now closed. It was in a Gaylord type contianer and was absolutely complete and unused. The fellow, David French if i recall, said something about modifying thr transmitter for RTTY, which i thought even back then, was a waste of a WW2 artifact. I don't know how many others were given out, but it was >1. So you have some other Navy activity paying to have TCS refurbed while NAS Samd Point has them unused in storage. Makes sense to me. Like post WW2 the military selling off power transmit tubes surplus while some other branch is buying them for the military's use. It does create make-work for otherwise underutilized employees. 

This reminds me: years back i had an ALUMINUM TCS cabinet. At the time i naively guessed it was for minesweeper vessel, but now it seems that guess was sophomoric and ignorant. So, why would there be an alu TCS cabinet ??

Also: did you know, some TCS receivers are more broad ? The TCS-5 was intended for vehicle use, thus the wider selectivity.

I used TCS set as my Novice radio decades back  with a surplus LC audio filter which made CW sound like throwing rocks in a train tunnel

. The setup did meet all the requirements the OTs recommended for a Novice beginner radio: insufficient selectivity, poor tuning resolution, fully manual break-in, a challenge to use.

-Hue Miller

A sunny but very windy afternoon sitting here by the Pacific Ocean.