Here's what consumers have asked with answers from Plumbworld.co.uk staff and previous consumers.
I have used them i9n the past and had good service
I have completed my purchase with Plumbworld. I used to live nearby although a couple of years ago so had seen their premises. Things can always quickly change with businesses BUT I have absolutely no reason to think they are a scam company. In my experience a legit company.
I messaged via ebay, fairly prompt replies, after i rejected the partial refund offered they sent a new replacement. So find no fault with this system.