My guess is that it's haddock (?) At least we can still get that.....or.....can we ?
I also guessed that it was an east coast thing......which it is. I came across this site that has a product list......Chicken Haddie is on it. (I have no idea where it is though....lol)
I wonder if Mr. LM also remembers Lobster paste (another treat we had as kids. Mom used to say that lobster to her was like balony, because it was regular fare where she grew up).