Linhof type lens panel for Wista 45

…do they always have an off-centre hole for the lens? Why are they like this? Does it cause the lens to sit below the centre line?

Linhof-made boards have an off-center hole because this centers the lens when mounted on the camera. As far as I know, other cameras are designed to use boards with a centered hole. But you can use either type on either camera at some sacrifice of rise or fall.

Exactly, it varies from camera to camera, and most of the time, where the hole is supposed to be is not mentioned in the user manual -- if you are lucky enough to have a manual.

It's easy enough to figure out by yourself. Just put a lens on your camera with the board that you have. It just needs to be a lens with a small image circle. Even a 35mm lens will work. Collapse the bellows as much as you can -- with the front standard centered at the ZERO mark, if it has one -- and see if the image is centered on the ground glass. You might be surprised, and you might need to make an additional mark on the front standard for where the lensboard need to be for a true ZERO.

Both center and off-center boards are available. I mainly use centered generic Bromwell brand Technika/Wista style boards for several view cameras, sometimes in combination with a Sinar board adapter.

Drop-bed technical cameras like the Linhof Technika and Horseman FA, and certain others differ in this respect from typical view cameras, which are apt to work best with basic center hole boards, unless you are determined to squeeze a little more rise or fall from the front standard.

I use Linhof style boards with an adapter on my Deardorff, most of my lenses are on off-center drilled boards, since those are most of what’s available.
It hasn’t caused any problems, even when I’m using the 5x7 back.