The wikipedia covers some of the P4 formulations, with and without cadmium or beryllium.

https://en.wikipedia.org/wiki/Phosphor

The table pictured is from a copy of U.A Sanabria's Television Course book published in 1948. The listing for P4 phosphors should use a plus sign instead of a minus.
Ed

The Motorola lives again! I had my friend go over the chassis. It had been professionally worked on, but with a minimalistic approach. Now it's been tweaked to be a reliable performer. The photo doesn't do the screen-shot justice. It plays like new. The audio is loud and crystal clear. Those Motorola TS-18 chassis are very good.

That is a beautiful set Joe. Congratulations.

Thank you. It replaces a very nice one I regretting selling many years ago. I sweated it out having it shipped to me!

a very nice looking set, I will not to replace original caps unless it doesn't work.

I agree. The previous owner who found the set had already worked on the chassis. My repairman replaced a few original caps that were okay, but bound to fail soon. It all depends on whether you want to use the set and enjoy it, or just have marginally "working".