Looking at the sellers site and the T&C's as quoted (on Ebay) and below, I wouldn't personally buy anything from them, especially after reading item 1 in the returns section, one clue is the grammar of the T&C's, which is always a give away.
RETURNS
1. If you receive a faulty item or change your mind, simply return it within 7 days for an exchanging the right one product. After that, no return and refund will be accepted.
2. The buyer is responsible for all postal cost incurred for any item/s which is returned in all circumstances.
3. If you have any query regarding a product please contact us via the eBay email system. We are not responsible if you contact us with an alternative email address.
4. Return items must have all original condition, packing, and accessories.
5. Return postage and insurance charges are non-refundable for items.
6. If the items are returned unused but packaging opened, that we cannot accept the returns due to Health and Safety reasons.
CUSTOMER SATISFACTION
1. Your satisfaction is our top priority; our aim is to make all our customers happy whilst shopping with us.
2. If you have any questions or problems please do not hesitate and feel free to contact us at any time. We will make every effort to respond to your inquiries as early as possible.
3. If you are not happy with our product, please do not leave negative or neutral feedback before contacting us, just bring in our knowledge and we will do our best to resolve the issue for you.
4. Please also look at our great items and prices on our eBay shop.
5. Thank you for looking and shopping. We are optimistic that you will continue to buy us in the future.
Regarding a Money Back Guarantee from Paypal, their T&C's state they will give a refund if.... the goods are not as advertised, as you have had and used the Item for 2 years(almost), I doubt they will help you, to me and no doubt many others, buying off Ebay is a risk, most of the warranties given are worthless, as so many of these adverts are from Chinese Firms, who will insist you send the item back to China, I know yours was, as far as you can tell not from China but off a firm in London, you have to be very careful nowadays buying online from anyone, no one seems interested when things go wrong, you only have to look at the response to Scammers, they always blame the person scammed, although it is obvious they must be able to trace the money that the scammers have goyt away with.
Good Luck on your Quest for compensation, but I wouldn't hold out too much for getting it.