Are you sure those are 27" rims? I know touring bikes have long chainstays, but the gap between the tire and the seattube looks like you're runnning 700c wheels. The difference it negligible (8mm in diameter), but it does mean you need the pads to be 4mm lower than if they were 27" rims. I don't really doubt you that they're 27", and the perforated braking surface supports this, but it just looks like the wheels are little undersized, and the angle of the pads backs that up.

• You're kind of stuck at the moment, as I see it, you have three options-
1) you can take the conical washers out from between the brake pad itself and the cantilever arm and hope they hit square and are toed (try it, you might get lucky)
2) you can get new cantilever brakes
3) you can use a wheelset that is built with a narrower rim so the cantilever arm has more swing before the pads contact the rim.

Edit: somehow when I clicked on this thread, this post was what looked like the first post. Sorry, looks like you have it sorted anyway. I typed it out, so I'm going to keep the post, maybe someone will find it useful. *shrug*

Edit 2: This time of year is BRUTAL for zombie threads.