Great question, we don`t offer a repair service but can signpost you to some recommended repair companies that deal with specialist repairs to products like tents, rucksacks and footwear.
In most cases these repairers act as agents for brands as well as direct with the public, so will have experience of the right repair and access to things like sole units or materials to match or give the same performance as the original component.
So for clothing like Gore-Tex, footwear, tents and other gear try
Lancashire Sports Repairs
Tel 01282 439109
Scottish Mountain Gear
Tel 0131 564 1000
https://www.scottishmountaingear.com/contact-form for initial contact.
We can recommend either company having dealt with both for many years.