Danny your description of the Leaving of Thornaby brings back long forgotten memories, of calling cards (I still have the rump enders, in their buff coloured cardboard box, along with the engraved copper plate ready to run off another gross if I should enter a space time continuum and start all over again), of the correct way to "PPC" as well as to arrive at a new Mess.
I've no idea if the "Customs of the Service" have been updated (do you now simply email the entire mess membership, or "Blog" them?). Even in the 60's it all struck me as somewhat archaic, like living out a PG Wodehouse plot. The first thing I had to purchase before even reporting for my first day's service was a "pork-pie" hat. That was in order that it could be doffed to all Ladies and to all Officers when one was in civvies. Moral; stay indoors unless wearing sports gear!
The Pewter Tankard was still the standard Record of Service as you moved from unit to unit. I got a rather fancy one on my last full day in Singapore. It had a glass bottom to it (so that you could check that it didn't contain a recruiting Sergeant's shilling before swigging from it). The inevitable happened later when, tired and emotional from it all, I dropped it and broke the glass. In a panic I went down to Changi Village (which could out-Harrod Harrods!) and they arranged to replace it by next morning with an identical one, fully badged and inscribed as the original, for a small consideration. I have it, and its sisters, still.