The latest video confirms that tag 4 of the terminal strip is part of the video signal path. Just need to see where it goes now!
The junction of R77 (100k) R76 (100k) and C58 +'ve (2uF) is at tag 4. If you look at the circuit, there is one path left to be traced, this is the line going down the page (on the circuit diagram) across and then down to the junction of R133 (10k) and C95 (100pF).
You need to let me know how many connections are being made to tag 4. There should be at least 4 but I can only account for three of the connections so far.
There needs to be a fourth connection that connects to R133 and C95. You need to find that 10k resistor to make any further progress.

NOTE: In case you're not good at reading resistor codes
10k = Brown Black Orange
100k = Brown Black Yellow

Good luck in sorting out that mess!

Here are our others!!

http://youtu.be/CGRms1alv00.

The mystery is solved. The yellow wire needs to connect to tag 4 of that tag-strip. The CRT end should then connect to the 10k resistor and 100pF cap on the CRT socket as stated in your video.
You probably have other problems to solve before you get a picture on screen but at least we have the wire connected where it belongs.