[cmoore330]

I was able to take some pics this morning and think you will agree that these are one in the same as yours. I took an assortment highlighting some of the things you asked for including pictures of one you have (SP-50) and of one from the series that you don't have (129-SP). I didn't take a picture with a tape measure, but they do measure 11x14.

Hopefully this is all helpful and brings you closer to the conclusions you are looking for on this set.