We have a Super Viking ready for new bellows. Any SV owners got a view on what's best and where's best to get replacement fitted. We are best in the beautiful north and could sensibly travel 1-2 hours from South Manchester.
I have a devon double top with a pvc bellows it was fitted by the po and made by a local ( to him ) lorry trailer firm as it was far cheaper than anything else. It's ok, gets a bit condensation on and holds no heat so the kids are well wrapped up when they go up top. It's about 9 years old I believe
I don't think you need PVC for a Devon unless it sticks out over the roof? You need it (or something sturdy weatherproof) for the super Viking as it cantilevers out a metre or so from the roof. We're getting a new one made with the Westy side and front window flaps, the PVC gets very sweaty when you're abroad in the sun!