I have a 2009 Landmark Pinehurst and the sleeper sofa air mattress has a leak, slow but steady, and will not old air all night. I have no idea where to look to find the leak. If someone might have a suggestion, I would appreciate your help. In lieu of that does anyone know where I can get a replacement mattress for this vintage sofa? Who is the manufacturer? This sofa is extremely heavy, well made and still looks great, but the option for anyone sleeping on the mattress is not good. All input is appreciated. Thanks.