I'm putting a balanced lug sail on my skerry.  it's my understanding that there is no change necessary to switch between the sprit sail and the balanced lug sail. You can read John's reply to my question here,  http://www.clcboats.com/forum/clcforum/thread/29175.html

I love the internet: a 2008 post surfaces!  Six years and many Skerry lugs later (that rig has eclipsed all of the other Skerry rig options as the most popular by far), I have changed my mind.  Let Google hereby archive my shifting position.

The stock mast and step are fine with the lug rig.  Tinkering with the attachment points for the halyard and downhaul yield proper balance under sail.  

Talking with many Skerry lug sailors (as recently as yesterday), I'm hearing variation in exactly where the downhaul and halyard should be.  The helm balance will vary based on many things, including outhaul tension on the sail, where the crew is sitting, and the skipper's helming style.  

Using the common CLR/CE calculation, this is how it should be set up.

Some builders have reported lee helm with that setup, which again could have a number of causes unrelated to CLR/CE.  But shifting the downhaul attachment forward on the boom will dial in more weather helm to suit:

One thing I've learned is that double-ended boats like the Skerry are much more forgiving of how you match up the CLR and CE.  They have no tendency to round up when heeled, for one thing.  

Personally, I still like the basic sprit rig:

Thanks for the responses, and thanks for the information and photos John.  

Yes, I like the sprit rig too John, but when you are an octogenarian-plus as I am, I'm betting you will opt for the lug rig as I have. Will be my first time as a "lugger: but I'm looking forward to the experience.

 I originally used the stock mast step and partner for a lug rig mast, but I steam-bent a 5 degree rake in the mast that started above the partner.  Now, I only sailed this about four times before the mast step failed (lousy epoxy bond)    However, I did not find any issues with lee or weather helm, so I think this is not a big concern.

On my last sail, the epoxy bond on the mast step failed...the mast fell over and crushed a bunch of plywood at the partners.   So I rebuilt the partners with some wood I got from CLC and another double-layer of marine plywood. I made a totally different mast step, and the new mast is a $50 piece of painted  2 1/2 inch diameter aluminum pole.  I've plugged the ends with redwood (light wood) and made a slot at the top for a sheave.  We shall see. I hope to sail the rig soon after  Christmas.

 Oh, and I'm not building any rake into the mast step / partners.  The wood mast I had before wasn't terribly rigid, and it bent quite a lot when I sheeted in hard.  I don't think the aluminum is going to have that problem! 

   Be sure to drill a hole in the bottom of the mast, level with the cedar plug, to drain any water that gets in there. 

  The tube is completely sealed shut with the redwood plugs and PL500  polyurethane sealant.  I don't think any water is gonna get in there!  However, if it does, no big deal. It won't do anything to the aluminum, and if the plug at the bottom of the mast rots out, no big deal. It was an hours project to make it, I'll just make another one.
What I wish I could have done was powder coat the aluminum, but the cost of powder coating a 13 foot long tube is prohibitive.