"The chassis is a ct2B and the number on the cabinet is 805."
ct 2b??? are you sure? I think that Ctc2B is the 21" version of the set.
The serial number is located below the big power resistor on the back of the chassis... sorta visible in the contrast enhanced picture. It can be seen even when the back is in place, through a little window.
jr
Update... I see Phil beat me with a better pix... oh well!