If I remember reading correctly, (my memory is suspect) I think John Z indicated that at Norwood they would make a stamp each day for every engine combination to be run with the date/engine code. What if it was done differently at LA such that they used 2 stamps, one for the date, the other for the engine suffix. They would only have to make up one date stamp each day, and not a stamp for every date/engine code. Just a thought.