Thanks, Tom. yeah, I think I will be a Large. Interesting you went from IH to RMC. I hear many going the other way. I think the pocket configuration is higher on the RMC, and the IH is in a more natural position. I don't know. Splitting very fine hairs when you start talking about those two brands, can't really go wrong.
No, you’re absolutely right. The IH is the “better jacket” in many aspects (nicer outer fabric, useful details like inside pockets and snap closures on hand warmers etc.).
It’s just that the IH is a generic “jacket inspired by a deck jacket” (although a very cool one), and the RMC is more or less a repro. I just find it a bit cooler. Since I have it, I don’t grab the IH any more. I live in a four season climate, but I hardly need two deck jackets in addition too the shearling and the wool coats.
I also think you will be able two pull off a “Large“. You won’t need much layering, and I am more or less in between sizes.
Fit pic.