While working on the HV supply, I discovered the Mycalex HV deck had some stress cracks. Probably from the tube being insert and removed over the years plus age.
It's an interesting material. Feels like stone or ceramic, but can be drilled and machined if care is taken.
The breaks were very clean and no damage around the tube pins. So, I figured I try to glue it.
First, I pressed the pieces very tightly together and wicked in some super glue from the back side. It flowed and bonded very well.
I then reinforced and filled in void with slow cure, high tempo grey epoxy cement.
Finally, I gave it a good cleaning. I think it will work.