If *I* really liked the jacket, I'd figure out a way to make a sleeve piece to replace the missing part. The hardest part of a set-in sleeve is getting the shoulder seam right, IMHO. Tacking on a modified tube should be reasonably easy...should be. Don't even worry about matching colors, as long as this is strictly a piece of backcountry gear. Keep the JWP nickname for the jacket as an explanation of the color.

If you don't want to work with down, consider making just that part from some other fill. The weight penalty shouldn't be too excruciating and the whole thing might just help you to remember to keep the good stuff away from heat. I messed up my Frogg Togg sleeves working too close or reaching around stoves. I hope to remember to pay better attention in the future.

Oh, yes-At least one outfit, Jacks R' Better, makes separate down sleeves among its wares. MAYBE they would sell you one sleeve or a partial one. It is worth asking.

Good Luck!

CamperMom