The Embassy Shop was located in building 302 in the West Compound, just around the corner from the service station. It was basically a discount liquor store, and without all those bothersome federal and state taxes that you have to pay here in the States.
No doubt there are many stories to be told about this place, but I'm afraid that mine isn't among them. I think the only time I was ever in the place was when I purchased a bottle of Napoleon brandy there. I had been invited to a local home for Moon Festival dinner and someone told me that it would be an appropriate gift to bring.
I know that booze was rationed, but I don't recall if there were separate ration cards for the commissary, certain Navy Exchange items, liquor, etc.
It's probably safe to say that some of the alcohol purchased at the Embassy Shop found its way downtown to the local clubs. For the record, I have no personal knowledge of any such goings-on.