I just read your Sigline and your Blog and realized you're on an RTW trip. Good for you. And good luck to you.
What Anton was alluding to is that sometimes you'll get a speck of debris between the seal and the sealing surface which can cause a leak. Using a thin knife blade w/ thin cloth to run along the sealing surface you can sweep the debris out (yeah, that involves sticking a knife under the seal lip !!! ). Another approach is to make a tool out of thin (like 0.008-0.016") plastic sheet (like a soda pop bottle), perhaps 5/8" wide and tapered like a knife blade, and 4'5" long. This can easily slip in under the seal lips for cleaning. Motorcycle shops sell a similar tool for cleaning under front fork seals. You seals sound damaged, but it wouldn't be a bad idea make this tool for roadside emergencies. Might save a set of brake shoes (spelled $hoes$).
Good luck on your journey, and keep the shiny side up. :)
'73 R60/5 Toaster
Luddite. Not just a philosophy, a way of life...