Yep, that's it. Just that. The undercollar padding-stitched to its wool interfacing. What I should have taken photos of was the stepwise process.
See the slight, curved fold? That's the roll line of the collar. The bit above that was padding-stitched first, then I had to fold the collar at the roll line, pin-baste it, and then do the padding stitch on the rest of the collar. That provides the structure and the shaping that it will need to keep the collar lying flat.
It's a long process, this business of doing things right.
The Kimono Vest is coming along. Both front pieces are done and I did up the shoulder seams using a crochet hook to give the shoulders extra support. I'm doing up the front band now. Actually, I already did the front band once, but I realized I hadn't knit on enough stitches and it was much too short. Nothing like a vest where the front band puckers the front to about half their length.
Ah, if only life allowed us to rip back and do things over.