Dont know if they still do them, but I am sure that Barrons at Herne Bay (the place on the road out to Reculver from the Thanet way) used to sell Sterlings (or their predecessors) In any case as they are part of a big group, they probably sell Sterlings somewhere so work done in their workshop may well count anyway.
It was when Barron's said that didn't normally do Sterlings that I thought I'd ask around to see if there are any others. I'm sure they're quite capable really but it's always good to try to get one that knows the vans inside out I suppose. Can't be any worse than the Richard Cranium I bought it from.
Discover Herne Bay are a Swift Group Dealer. They sell all of our brands except for Sterling. They can do the warranty on your caravan and I am sure they would do a good job for you.
If you want other options you can either use our website www.swiftleisure.co.uk and find a local dealer by using your postcode or you can contact us enquiries@swiftleisure.co.uk or our telephone number is 01482 875740