7JP4s create some additional problems. We would have to have stems made. Shipping of these tubes is an issue since the guns are so delicate. And, I don't know of anyone who has done an electrostatic tube. It is probably possible, and we will investigate it, since there would be a huge demand for that tube.
Here is a progress report on the project:
http://www.earlytelevision.org/crt_project.html