I got a copy of that Sams and dug up a yoke from an RCA KCS-47 chassis using a 16GP4. That has a 70 degree deflection angle just like the 16" CRT in this Capehart.
Even better, it has a 56 and 270pF cap inside just as shown on the schematic.
Best of all it fits. Here's a dry run with a 16KP4. I think I'll use a little 8XP4 bench CRT during the restoration.
I then proceeded to test the flyback, focus coil, vertical output transformer, etc. It all checks out - even the huge candohm resistors
Finally, I pulled the 5U4 and fired it up. All the tubes lit and I have about 5 volts on the 5U4 filament and ~700 on the plates.
So it's full steam ahead on this project
