I decided to replace this mess, but didn't want to use the same material as I thought it would deteriorate in a similar manner. I found some VELCRO in the local DIY store (the packaging was damaged and it was going cheap!)and so I thought that the loop side would be perfect to replace the foam seal.
This is on my list of jobs to do when I get a dry spell of weather. I have been looking for a suitable alternative to the foam strip and wandered if the Velcro has stood up to the test of time seeing that David had originally installed it over six years ago.
What I have used some years ago is some self-expanding (but compressed delivered) band of foam as used for buildings (like seal a window). This is available in various sizes, the thinnest is 1-3mm thick (1compressed, 3expanded).
Please make sure you open the 'wheel' with the band just shortly before using, or it will be already expanded.