Barling? D.Simpson LTD Edinburgh, "Arcadia" British Made

This is your lucky day. One of the world's top Barling authorities---Jesse Silver---frequents this board. :D
He will doubtless be along shortly. ::

The stummel certainly looks Barling-like, but the markings don't ring any Barling bells (at least to me). Pipe shops like Simpson would have bought pipes from any number of manufacturers, so I don't think that the Simpson stamp suggests it's a Barling. (By the way, both of those pipes you linked to are mine. :D )
Hardcastle marked their pipes "British Made" -- I wonder if that's not the maker?

I agree with Pitchfork. In my experience pipes made by Barling for retail tobacconists often if not generally had the Barling name stamped on them; certainly the two examples given in the threads you cite demonstrating other possible Barling made/Simpson sold pipes suggest that.
A few other thoughts. First, David Simpson first appears as a tobacconist in the Edinburgh city directories in the 1878/79 edition. He was originally located at 30 Forrest Road, but over the next three decades opened shops on Princes Street, Great Junction Street, and North Bridge. Apparently about 1908 the business reorganized as a limited liability entity, and thereafter appeared in city directories as David Simpson Ltd. Immediately thereafter it expanded to a variety of other locations on Princes and Rutland Streets. From what I can tell it continued to exist at least through the mid fifties.
Second, A. Oppenheimer manufactured a model named Arcadia for a number of years (from at least the late twenties through the late thirties), and in fact had the name trademarked. To me this strongly suggests that the pipe was made by Oppenheimer or one of its affiliated (through Cadogan) companies.
Putting it together my best guess would be that your pipe was made by Oppenheimer, and produced sometime in the 1930s or in the period when production slowly recovered from the disruptions of WW2 (starting about 1947). It's certainly possible it dates to a later period than this since I don't really know when Simpson went out of business or when Oppenheimer stopped making the Arcadia.
Incidentally, better pictures of the nomenclature might help someone here to offer more insight into the origins of the pipe.
In any case it's a beauty; enjoy it!

That IS a beautiful pipe! But as Jon writes, the nomenclature points to a different maker. "British made" wasn't a Barling stamp, nor was "Arcadia". Who Made That Pipe? lists Oppenheimer as the manufacturer.

Although I suppose that the same looking stinger could be in a number of different make pipes, one like this was in a BBB pipe that I bought last week.