Base Camp Suspension are a Cane Creek service center if you want one in Scotland, they were booked up last time I spoke to them, most places are busy!
Personally I am not a fan as Cane Creek will not sell service kits or provide service info.
Somebody has kindly uploaded the Double Barrel service manual
https://drive.google.com/file/d/1LUkNBln5uRmWb-D7mJBOHQ4JkrBTpetZ/view
You could always send it in for a service, most places will call you if anything beyond seals are damaged, then make a decision based on the price of any additional parts.
Most services will have short warranty (3 months for TF Tuned), a new shock will normally have a 2 year warranty. (if that is a consideration for you)