We found 1 Reddit comments about Cento Sliced Pimentos, 4 oz. Here are the top ones, ranked by their Reddit score.
My bet would be to try Kakulas Bros in Northbridge first, and then maybe pop in to some specialty/international grocers and ask if they've got them. They're the little red buggers in prepared spanish olives. Get a jar and dig em out maybe?
For the life of me I can't imagine what sort of American recipe you're making that requires these, and I'm an American. Dafuq you doin?