Question.
How many of the Cambrian Coast variety of the 197s are in use OR have been used ?.
I believe that the Cambrian ones are twenty-one 197/0s => 197003, 197022-197041 ?
Correct, the ETCS-fitted (Cambrian lines main/coast) 197s are 21x 197/0s numbered 197003 and 197022-197041.
7 of these have so far been used in service (I believe with the ETCS isolated for now) as normal 197s on conventionally-signalled lines:
197003/028/029/030/031/033/034
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All 56 non-ETCS 197s (30x 2-car - 197001-197002, 197004-197021, 197042-197051 and 26x 3-car, comprising 12x 188-seat - 197101-197112, and 14x 174-seat - 197113-197126) have been in service,
plus the 7 ETCS-fitted 2-car 197s mentioned above (197003, 197028-197031, 197033-197034) = 63 197s that have been in service (37x 2-car and 26x 3-car),
leaving 14 197s that haven't yet been in service (all of which are ETCS-fitted 2-car - 197022-197027, 197032, 197035-197041). Once those 14 have all entered service then the number will of course match the build quantities (77 total units, comprising 51x 2-car and 26x 3-car).