Peter Briggs got in touch and was pleased that some of his squash doubles wisdom was disseminated via the blogosphere. But he thought that a few changes would optimize his primer on the game. I have made those changes in red, and are available for viewing here.
On another matter, it does indeed appear that SquashZAG has unfortunately folded. It is a very tough job to do a full-time website largely by oneself, and it can prove expensive as well. The pressure eventually became too much. Too bad!