Rolled up for 7 years is a long time. If I was going to buy it, I would go for it and inflate it once you unroll it. If there was residual water in the raft or if the storage unit was wet, you may see any damage or discoloration right away. I would inflate it, soap it down with detergent and water(especially  seams, patches, and valves), and note any leaks, rotting material, or holes where mice etc may have snacked on the Hypalon materail You might want to get it in a heated garage and leave it inflated overnight to see how it holds air. Also look for flaking or cracking of the outside material. Riken has had issues with older boats dry flaking which lead to leaks. Check the last two numbers on the serial number, that would tell when the raft was manufactured. Good luck and let me know if you have more questons re this raft. Lots of things to consider with a boat rolled up this long. jc