I finally got the barrels removed from the action.
A previous person had bungered-up the shell ejector cam, causing it to hang on the release rod, rather than camming the release rod that "oh-so-tiny" distance so the barrels would snap past the normal opening angle.
All in all, there is good news and bad news. The good news is that all the serial (22197) numbers match (stock, trigger group, action, barrels, and forend). More good news is that nothing metal is broken. Mechanical metal repair only required some judicious diamond-file action to clean up the previous person's mistake. Oh, and the usual cleaning of recessed parts and orifici.
The bad news is that the stock is cracked at the action.
The action is a "slight" bit loose in the stock, as a result. My guess is that a previous person tried to "whack" open the take-down by pounding on the stock. As I reported, that was futile because of the bungered cam on the shell ejector.
Instead of using brute force, I removed the trigger group and used a brass punch to drive the release bar back sufficient to fully break down the shotgun.
Now the question is, what is the best way to repair the stock
? All the wood is there. I have no clue how the action comes out of the stock. It looks like the side plates are pinned into the wood.