Dr-Nab, take a print screen shot of the pages and the images, and then save to your hard drive. etc
Then send a bill of £50/day for unauthorised use from date of letter, and then offer a one off royalty of £625 to keep using it and to stop fees spiralling for them etc..
thats what i have done in the past, and it generally works well.
i have draft letters of a legal claim, and basically, they have worked in the past for me if you want to go down this route.
But dont send too much info about yourself on ebay, as you need to come by professional etc.