How to vertically center-align a new TV to a pre-existing wall-mount

Question

I'm replacing an old TV with a new one and I want to wall-mount it using the old mount. In the new TV, the location of the VESA fitting isn't exactly where it is in the old one. I'm using the Barkan E30 mount, and it looks like it the beams can be fitted into the wall plate in three positions. I can't figure out from the schematics where exactly should they be screwed so it's vertically aligned relative to the wall plate that's already wall-mounted.

Basically, I'm trying to figure out the dimensions marked in questions marks below the schematic:

This is the existing mount:

Old TV:

TV models:

• Old - LG 37ld460
• New - LG OLED48C1

Answer 1

If the vertical brackets have only one mount point on the horizontal bar:

1. Put the vertical mounting brackets onto the horizontal bar on the wall.
2. Put a piece of tape on each vertical bracket at the center of the horizontal bar.
3. Measure the TV to identify its vertical mid point.
4. Line up the tape marks on the brackets with the mid point on the TV.
5. Attach the brackets to the TV so the mid point marks line up as close as possible.
6. Hang TV on wall.

If the vertical brackets can mount on the horizontal in more than one location:

1. Put the horizontal attachment point at the vertical mid point.
2. Line up the vertical mid point of the brackets as close as possible to the vertical mid point of the TV and attach to the TV
3. Hang TV on wall.