I have done a couple of versions of stuffed squid here but took them down the Asian route.
This is where I started from I think it was maybe 1980 I cooked this.
This one is baked ,I will stuff them with chicken mince,onion,pancetta,fennel tops,,breadcrumbs,raisins,pine nuts,lemon zest,then make a tomato sauce with fish stock,white wine & bits.
Bake it in the oven .I think its fish stock,home made I didn't label it,couldn't get fish head at the fish shop & wouldn't pay $8 per 500ml for gourmet seafood broth at the deli.If its not fish its chicken to hard to tell frozen.
I will get some photos up as I go.