Thank you all! My Philco arrived last Saturday and works fantastically well--I'm in love with it. It just needs to have the gasket around the outer door replaced as it's badly dry rotted. It's my understanding that Philco came up with the inner door as a way to get around Crosley's patent at the time for door shelves.
I've actually come across Philco Conservadors as early as 1939, so this design has been around for quite some time, but the glass inner door is apparently a 1948 design, and oh SO cool.