Cheeses like Miller’s and HaOlam are usually KFP year round, so it would be good to buy this ahead, as well. Same goes for AB Gefilte Fish, and anything else that is KFP all year round.
One would certainly assume from this sentence of yours that all A&B gefilte fish is okay for Pesach. It was only later in the thread that, when shown your error, you conceded that it’s only one type.