I had to look them up Leo.
The reason I don't have them at my fingertips is that they don't apply to business-to-business transactions. They form part of the consumer protections which you kiss goodbye as you walk past the sign that says "trade counter", or open a "trade account", or ask for a "trade discount".
But assuming that the OP was dealing as a consumer -
Generally speaking, it does give the right of return - even with opened packaging - within 7 days. There is a long list of exempted items (like CDs, software, perishables, items of personal hygeine, customised items etc) to which this right does not extend. The list cannot be exhaustive.
The explanatory section of the regulations says that the consumer should have the same opportunity to inspect the goods that he or she would have had in a normal shop. This is a tricky one - some merchants may have a few models on display (more likely empty cases) but certainly couldn't display all models. Consumers would not normally have the opportunity to rootle about in the merchant warehouse, unboxing products.
Generally speaking, the courts tend to side with consumers, so the OP might get away with it.
Edit - Auctions, including online auctions, are also excluded from the DSR. So if you buy on Ebay auction you are surrendering your DSR rights.