Second Flight Mags?

Stumbled upon this 1.5L of 2012 Screagle Second Flight over the weekend. I know plenty of folks on the list (for both the Estate as well as the Flight), but none had ever heard about this before.

Anyone ever come across a large format Second Flight?
sfmag.JPG

They make mags of Screagle. Seems logical that they would do so for Second Flight.