try Vanhaus in rugeley tel: 01889-570756
very similar to another swivel slide double base seat unit listed on here, but better finish and saves you about £70 !!!!
ring adam at vanhaus.
search the site for all seats available .A A:
Just make sure that you will not be taking tall passengers as I had a touch of class double swivel (well made, but a but diddly to use initially), and they do raise the seat height. I'm 6,4ish and found the roof became a problem!