$48 Hallicrafters in OK
 

OK it's a mid 50's 21 incher but it looks nice and it's cheap!
Looks like it might have a metal cone CRT though.

http://cgi.ebay.com/Vintage-Retro-TV...item2c5d6534b3

Were there ever any large-neck, metal-cone 21" CRTs? I was thinking maybe this was a 17" set, but the dimensions seem more like a 21" as you said, Eric.

I'm pretty sure there were 21" metal tubes, we know there was a 30 inch one.
I was just guessing about this one being a 21 inch but it looks like one.

Here's a page with a picture of a 21AP4:

http://evilfurnaceman.tripod.com/id16.html

I don't think the HC set is metal, you can see wires going sround the outside of the tube that would not be there were it of metal contruction. I think they are grounding the outside of the dag coating, so it's probably glass.

21MP4 is another metal rectangular tube.

For sure the set has a metal CRT... the joint area between the glass section and the metal cone is visible in both chassis pictures, and the faceplate appears flatter than a glass 21".
I have seen a metal 27" rectangular CRT (27MP4) which also had a flatter faceplate than an all glass CRT of that size.
jr