[6GH8cowboy]

When Ive done this before the wedges get loose as the separation gets closer to the center. I suspect the fail was due to a lone tight wedge when the progres stoped and possibly temperature change came into play. My method is to dig out some pva and gently tap the clothspin wedge until I sense the First tight response after the dull taps of pva intrusion. On a nice hot day the "fingers" appear and travel to the center until the final pop, glass intact.
I have most of the broken material off but the middle section is very slow going and Ive not found a sample even slightly water soluble. or paint thinner, or accetone, or brake cleaner.

The CRT with the fingers was a previous removal on another CRT. The fragment picture is the current project.