Hi Chris,
I dug the Edgwick manual out this afternoon, I've scanned a few pages which might be of interest - there's line drawings of the saddle, and the taper attachment, and a parts list for each. The main manual is just an operator's guide though, not a service manual, so it doesn't describe taking it apart (or putting it back together afterwards)...
Maybe now there's at least 4 of us with these old Edgwicks (there's a guy in Perth, Australia who has one, although he's not been here for over a year now), it'd be worth knocking together a Haynes-style manual? I'd be willing to have a go.... except I'm only good at taking stuff apart, always been rubbish at putting it back together again!