There are some YouTube videos about the Hebridean. Here's a link to one of them

https://www.youtube.com/watch?v=kkT27vR6yoM

And a some blog entries starting here

https://tammynorie.wordpress.com/2015/07/12/building-the-hebridean-wind-vane-self-steering/

Hope that helps

There was some discussion in "A vane gear for Weaverbird" . And a photo album is here.

Correct, Arne. In fact, it's perfectly possible to design a gear either way around, but I prefer to have the two primary linkage lines this way around so that on a dead run, or running by the lee, they are not going to rub against each other.

A pushrod and crank primary linkage takes rather more engineering to make, and to get the weights balanced up properly, whereas the small Dyneema lines used as a primary linkage are easy - especially now that I've found that the Barton and Antal rings are all that is needed to change direction, no sheave required.

I have John Letcher's book, but not the AYRS publication.  It seems to me from figure 6-14 that there is a major disadvantage to Jock Burrough's arrangement, in that whenever the course is adjusted, the lines to the tiller must be adjusted as well. This would appear to make it difficult to get the boat to settle onto the required course accurately and quickly. The arrangement in 6-11 is better but is still not very usable. A better arrangement for a running line gear is shown in Bill Belcher's book, page 104 - 106, and I have used a similar vane successfully, albeit with an angle of inclination on the vane axis, of 15 degrees or so. Photos here. Better still is to discard the single, central sheave immediately under the vane drum, and lead the linkage lines directly down to a turning point that is far enough below the vane drum that the angle between the two parts of the line is quite small. Then the vane turret can be rotated through 300 degrees without unduly changing the tautness of the lines, leaving unusable only the head-to-wind sector. See the arrangement of my current gear here.