I have confidence in my own work, so I replace foam surrounds myself. It is not particularly hard if you are handy. Kits can be purchased from various vendors, such as Parts Express. DIY is fun and, when you are done, you know that the job is done right. Errr.......or that you screwed up totally and the driver is ready for the dust bin as you say on the other side of the pond.
I would never mess with rare Altec or WE drivers, those would go to Great Northern Sound. Likewise, if I owned very expensive modern speakers, they would go back to the manufacturer. But for your Kendal drivers, I think that DIY is a great opportunity. While you have them apart you can replace the caps in the crossover and maybe some wire as well. Good luck.