Thanks Fred and Denny for all the help on getting this radio going.

I got the OZ4 tube (ordered from the site Fred mentioned above and got the tubes within 3 days of placing the order) and plugged it in. Voltage output on the K post of the OZ4 tube went from 8 V DC on the old one to 250 V DC on the new one.

Powered it up and it plays like new.

Thanks again