There are many companies specialising in upholstery, don't know if you'll find any in the Isle of Wight though.
One I have used myself and was very happy with their service and the result was Regal furnishings https://www.regalfurnishings.co.uk/
bit of a way from you but they will allow overnight in their yard with hook up.
Perhaps an idea for you is to check out boat renovation companies, there are more than a few in your region, or simply Google motorhome upholstery.
Oh and welcome to the site.