the first crt rebuild for my ctc10 worked great for about an hour.
then the neck cracked. they had no 21" tubes to replace that one with so i sent them one of my duds. it works great. it seems yours was like mine had a weat spot where the glass was joined at the time of rebuild. i have a new in box 21fjp22 and a 21cyp22
and an extra 21fjp22. no they are not for sale at this time. i see them going up in value everyday if you can find one grab it.
steve