Well, I hope it works for you - maybe a little bit of tinkering or doctoring on your part and it will bring back that food memory.
The pimiento used to drive me nuts when I would get a yen for this. Even the tiniest jars have more than a Tbsp in them, and I would always end up with tiny little bits of pimientos frozen in my freezer for "some other time." It was never enough to use for the next time I made Corn-Oyster Bake, so I'd have to buy another jar and keep up the cycle.
Eventually, I began cooking with more pimientos, even making my own pimiento cheese spread, so now I buy those big jars, lol!
Believe it or not, they really are integral to the flavor of this particular dish. I think it was originally a Christmas or Christmas Eve "special dish" and you were supposed to put a parsley wreath on top, with pimiento holly berries, but we never did that part. Somewhere along the line, the pimientos just stayed, but the parsley didn't. (I do put some parsley in mine, too.)
Wish I had my own real recipe to give you, but I realize this may not be the dish you're thinking of - at least I can vouch for it firsthand.
You scalloped corn and oysters sound wonderful. I think I just may have to try it out. I'm not a huge fan of cooked oysters, to me they are best icy cold and raw. But since we moved to an oyster area, I've been getting a bit more brave with experimenting with cooking them.
My folks, who are originally from Iowa, have homemade oyster stew on Christmas Eve. I think Mom makes it in a way similar to homemade potato soup. But since childhood I have not cared for oysters, so I never tried it; I do associate the smell of oyster stew with Christmas Eve.
My folks are in their 70s now, still married, and still in their own home, for which I am grateful. Mom still cooks.