Not about the Pamir as such, but in response to:
Originally Posted by JET
....In an article written in 1950 about Harry's experiences on that voyage, he mentions that they signed off articles in Penarth, so I assume that in those days Penarth must have been the designated address for both Barry docks and Penarth.
I personally have signed on and off in Barry in the 60's and Barry was stamped in my Discharge book.
My discharge book was issued from the Barry office in 1955, and I signed off my last voyage in Barry in 1960.
Given how busy Barry Docks were long before the 50s, I'd be very surprised if it didn't have its own MM Office long before then.
Penarth did have its own Mercantile Marine Offices, but I don't know when it ceased operating. See screenshot...