Look closely at the photo on the Skerry's webpage here; the becket block's lashed to the boom, then the sheet runs from the becket down to a pivoting block (mounted on the board trunk?) in the cockpit, then back up to the boom block, finally down to the crew's hands.

I'm surprised there's no page showing how to rig a lug sail in your instructions.

That setup would provide a theoritical 3:1 mechanical advantage, possibly necessary with the sprit sail shown in that photo, but I don't really know.  With our similar (possibly identical) lug sail on our lug-rigged Passagemaker, we put the becket block on the lower end to act as a turning block and get a 2:1 mechanical, which is entirely adequate for this sail even when it it blowing hard.  Makes a tidy arrangement, and, if memory serves, is more or less consistent with what was shown in the manual.

Here's a link:

https://www.dropbox.com/sh/bai86cb03j1hrdo/AADslGFOVsKHnp1-TGJiU1bfa?dl=0

...to a Dropbox folder with photos of our boat, getting things rigged up (some experimentation with that) and then the first day sailing her and a couple of photos a friend took some time later.  Let me know if that Dropbox business gives you any trouble or if you have any questions.

.....Michael

Thanks to both of you. Very helpful and way simpler than I thouht it was going to be. I think I am ready to take her out.

Regards, Wayne