Where to get picture tubes?

[WISCOJIM]

Originally Posted by Bobby Dip

Hi Jr, no the yoke does not slide.

Sure looks like it has an adjustment for it. (circled in red)

Edit: Guess not, I see in other pictures on the ETF site that the adjustment on top of the yoke would prevent this slotted adjustment from being used. Or is the metal plate under the wing nut also slotted? If so, then the yoke should be slide-able.