Your observation is correct. The Imperial was intended to look longer and slimmer than the OG Herc.Good call. I think high chest pockets tend to elongate the body and contribute to confusing proportions. Lowering it or setting it at an angle would make a world of difference.
The OP’s jacket looks large to me. Sleeves could be tapered and shortened a bit, and the back could come up above the rear pockets. I think this fit looks fantastic for the pattern:
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Thing is that it doesn’t look like this right out of the box.
Mine (v2) day one:
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Years later:
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