The actual stash is in a refrigerator below the kitchen/recreation area, where there are a few mirelurk corpses on operating tables and chain hooks hanging from the ceiling. Approach the right hand refrigerator of the two standing side by side, even if it is shown as "empty," and open it. If you are holding the Anchorage stash key, which you got from the utility closet with the broken door, or if you have high Perception, you can open a hidden compartment for 240 caps and a mirelurk cakes recipe.
The stash is hidden downstairs in one of the freezers. Rocky set it up. You know his style. Don't forget the key -- you'll need it to unlock the compartment.