There would have been nothing worse than opening an old bottle of wine and finding it had gone off.
I knew an elderly person who received a gift of an early 1800 first growth from another elderly friend that passed away and that was an enthusiastic wine collector. He had kept this bottle all his life and left to her in his will. Anyway, she decided to drink it rather than sell it and it was corked. Not a very heart warming tale, I grant you.
You gave a good sense of the Port in your description. I suppose there's a basic formula to writing these things, that I always forget to follow, and basically addresses the colour, clarity, bouquet etc. etc. in a set order. I tend to just think of what tastes and sensations stood out the most to me and write them down as that way also works, as your portrayal is testament to. I sense you wrote what you perceived from the wine and that DID lend clarity to your report.
On an ancillary note, I often wonder about whether people taste the same things when they drink wine. I've been with people that have claimed to detect things that I for the life of me could not. I suppose that it all turns upon how we are built and how we detect certain chemicals via our tastebuds and the like, and we cannot all be as proficient at tasting/detecting all the various molecules that go into forming the, i.e. chocolate or grass flavours, within each mouthful of wine.
Food for thought, if you'll excuse the pun. I seem to be doing that a lot lately - yesterday I told the barber to only take a hair's breadth off the top as I'd only had it cut recently sigh, I am beyond hope.