I have a similar size to you. Both of my feet are about 10.5D on brannock. I have a slim heel and a slightly wider forefoot. When I went into Alden D.C. earlier this year, Kathy measured me a surprising 9.5D on the Van last penny loafersm because 10D was somewhat loose. I do suggest that you try them on.
given that you have read the entire thread, you must have came across Namor's chart, I would say go with that chart. I went TTS on my Marlow wingtips and they are a bit loose, but I like it that way. The best way for you is to buy two sizes from RL.com and try them on and see how you like them.