I went back through the Scantlings and found an article for them in April 2008. They were avaialable through the guild store. I looked and didn't see them there so I emailed the guild store and here is the response:
"Morning Brad...they are not available at the moment. We are in the process of trying to get them again. Our supplier decided not to make them and we are trying to source them from a different vendor.

I would say to check the website in a month or so...we should have them back by then or at least know if we will be selling them again.

Thanks for the interest.

Sue

Sue Warden
Business Manager
Timber Framers Guild"