Thanks for the replies. I had initially thought the same thing from the mask. Until I remembered that Bob Andersen posted about the exact same set some time ago. I found that thread and he definitely said his set has a 19AP4, and his set has the same mask as well. "Inside the cabinet" photos of both his set and the one I am working on look like they have the same size CRT too. If you look towards the front at the mounts and distance from CRT sides to edges of cabinet they look the same. But a 3 inch difference can be almost impossible to identify by these pictures.
Bob's thread:
http://www.videokarma.org/showthread...ght=new+yorker
Thanks for the further info about the SC sets and the Dumont sets. I bet this is a 16AP4, after hearing that things like this were done back then originally. I will just pop it out and measure it to be sure. Thanks.