It finally seeped into my brain that I hadn't given any thought to the *back* of the coat. Oops!
Obviously, there are differences, seam-line-wise between this:
(click to embiggen)
However, I absolutely do not have the yardage* to slavishly copy how the original item is cut (caveat, the above is actually Abbyshot's replica, but it's a good-enough reference photo), so I'm sticking with the princess seam into the armhole in back, as per the Vogue pattern.
But I would like to re-create that inverted box pleat at CB (I'm rather proud of the fact that I managed to do so on a freakin' bolero jacket) and I'm giving thought to vent in back, too, although I probably shouldn't - full-cut twirly-butt coats don't need a vent for movement, because of that aforementioned fullness.
Anyways. Glad I looked at things, as I'm on the verge of tracing out the test pattern (just doing the top half of the coat - no need to burn up yards and yards of muslin) and I would have kicked myself if I'd missed the CB detail.
I'm reasonably sure that the lapels are going to be wider than I am**, when all is said and done, but for this first draft, I'll copy the pattern bits as closely as I can (as I've NO experience in figuring out such things, myself) and see how it looks. THEN I'll adjust. The Idris bodice experiment has taught me that I can't introduce too many changes at once, as I'm just not skilled enough at pattern manipulation to handle that. That said, I'm putting the pleat in for this draft, as that nicely fixes the problem I was having re: ease in the back vs. desire to keep the coat as closely fitted as possible, despite it being an overcoat, etc, etc.
*I have five yards, so it's going to be a squeeze, however I - ahem - cut it.
**I'm not kidding. My shoulders are 3.5" wide. The lapels, once sewn, are 3.5" wide. It all depends where the roll-line falls, methinks.