Early Color tube in 1958 article?

[Eric H]

Take a look at the bottom of this page, the picture with the caption "Student Benefactor Philip T. Di Pace, of Albany, N. Y., contributes used radio and television chassis"

http://www.rfcafe.com/references/rad...lectronics.htm

Is that some type of early color CRT or just a metal cone B&W with a mask attached.
It doesn't look like a 15GP22 and I can't think of any B&W sets that had the mask attached to the CRT like that.