First, you can see what happens when I re-knit with yarn that has been kinked from blocking. And it "almost" looks like I twisted the stitches I picked when continuing the stockinette. (I don't think I did...) The stitches have a different shape. Fingers crossed that will resolve itself with a second blocking.
I took a tip from Nancie Wiseman. She wrote in The Knitter's Book of Finishing Techniques which is my go-to source of "how-to's". She doesn't address seed stitch, but there was a kitchener method of using waste yarn that I thought might be helpful. I added an extra row to both ends using waste yarn, and attempted to duplicate stitch over it. Here's what it looked like (not a pretty sight)!