68/69 383 Big Block Factory Cast Iron Intake 2806301

OK so I just went on eBay to see if there were any of these manifolds for sale on there and there are two of them. Both of them have the same style date code as the one that I have. The first one has 10-10 so I figure it's October 10th and that is all that is on the date pad, the second one has 4-21 so I figure it's April 21st and that is all that is on it's date pad nothing for the year so I am guessing that the 5 - 1 5 on mine is May 15th now this is just a guess but looking at the other two it makes sense.
Bob