Is that a preserved specimen? It looks like it! To me your purplish solid structure looks like a full caecum. Many squids do the bulk of food storage/digestion in the caecum not in the stomach. If it was N. sloanii I'd say it was the caecum containing a (large) meal of cephs and perhaps some crustacean such as Euphausiids (the eyes can make the contents quite dark). The tubules behind it look like pancreatic ducts. The small sac at the end of the gill is one of the branchial hearts.
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