Need help identifying antique printing press equipment

Found this recently at a flea market in Connecticut. I bundled a group of things together including this and paid $55 in total, so I probably paid around $10 or $15 for just this. I believe it is a printing press tool based on the shape/design and because there are a couple printers block letters that I found inside. Many markings throughout, one I noticed up front is F-15 SPEC. Not sure of the exact function or application so any input on what this is would be highly appreciated.