In reply to DaveHK:
On my 1957 paper copy of the 1955 no. 26 inch/mile map, only the three south-most corries (Coire Each, Coire na Feòla, and Coire na Poite) and the northernmost (Coire Gorm Beag) are named. What the B3 landranger #24 names Coire an Fhamair and Coire Tol a' Mhèine are unnamed. I don't think this was due to lack of space because of the slightly smaller scale, as the earlier map sets names at angles and along curves as needed, and there seems to me to be sufficient room.
Fwiw the naming, or not, of the various lochans around the corries is consistent across the two maps.
(Out of interest, I wonder when the OS started setting place names horizontally-only? From a quick glance the current landrangers and explorers seem to only use angled text for names of roads / rivers / geographic features etc.)