I will post a picture of portly in this outfit soon, hopefully.
Here, I resected the old collar onto the raw edge of the new jumper. Not bad, huh! I used a blind hem stitch, but not a blind hem foot. For some reason, my foot is designed such that the needle slams into it and breaks and almost pokes out my eyeballs with flying shards of evil. I guess the obvious explanation would be that it's the wrong foot for the machine, but I swear I've used it before with no trouble, and I can't remember what was different.