Grease on the barrels and receiver parts- hard like varnish. Is this same grease also on the stock and forearm as well? And at present you cannot open the gun, nor remove the forearm and the barrels from the receiver in the usual manner? Wow-- this is a "puzzlement" indeed.
I know how we'd remove the Cosmoline from the bores of the Garands and Soringfield 1903's in the Armory- but that was just on ordnance steel and no stocks- also mainly in the bores, then the barrels were wrapped in special rust proofed brown paper and taped closed for shipment or storage.
Perhaps a form of paint stripper such as Formby's or WATCO, but try it on the barrels as see- wonder what the wood finish on the stock and forearm is like under a layer of that hardened grease? Good luck indeed.
Maybe like military Cosmoline??
Hybrid Mode