Its just the yoke clamp. Just be sure the missing piece is not
laying on the chassis ! The clamps on RCA yokes & blue lateral , purity
ring ass's tended to rot away. Replace with any clamp from a
90 deg delta CRT. Dont use an OTC clamp for a car etc. It may be
magnetic.
For CRT set-up follow the Sams til you get stuck then ask. If you
mark where things were you can go back to the start if needed.
Remember a few things.
1) Most of the adjustments are for the CENTER of the screen.
2) Ignore the 12 adj on the conv board till the end.
3) On big sets its better to lay across the set & look directly at the
screen.
4) For your first few set-up jobs a DOT pattern is best. After a few you
can do it by eye.
5) Be sure the TV is getting the best B&W pic you can get first !
enuf fer now
73 Zeno
LFOD !