I agree that a magnifier is something you'll rarely use. My TV-37 happened to come with a magnifier with a homebrew stand. A magnifier restricts the viewing angle so that your face needs to be directly in front of the screen. It can also pick up a lot of glare unless the room is quite dark. In this photo the magnifier reflects a fisheye view of the messy shop where the photo was taken.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html