Here are some pictures I took (in the fall of '97) of an engine that started out destined for a '69 COPO Camaro back in 1969 but ended up in a '69 Chevelle. You can see on the front pad the T0528MNQ. The first factory stamping would have been T0528MN.
There was an attempt to remove the N from the deck as there are punch marks disfiguring it. The lower half of the Q stamped next to the N is very deep. Probably due to the cylinder head being installed they did not get the font (metal punch) square to the deck.
The Chevelle VIN 19B403448 is also stamped on the deck pad.
Block is a '512 casting with a date J22 8. The cylinder heads were '840s cast C25 9, and C26 9.
Makes you wonder whether there was a shortage of MQ engines at that time, or maybe the MN engine was shipped to the Baltimore plant in error and they just improvised.
Chris White from Massachusetts had the '72 Z/28 this engine came out of back in the fall of '97.