Rehoming my cat due to moving for sale in Boston Harbor, Washington

I'm only asking for a rehoming fee to be sure that he's going to the right home and for the right person or family this can be waved. 
He's a very social cat, but doesn't get into your face. He loves people, cats, and dogs and has never had an issue befriending any. He looks just like a cat version of a cougar. He will let you know when his food bowl is empty, but I have yet to meet a cat who doesn't. He's 15 years old, no medical issues and up to date on all shots, I have all his most up to date medical records. He's on a grain free diet of mixed dry and canned cat food. He can easily convert but it would take a few days of food adjusting. He can be quite playful when he wants to be (feathers and small fluffy balls are his favorite) and enjoys most days sleeping or cuddling in your lap for pets. 
He would like to be an indoor/outdoor cat, but since he has no front claws I've been hesitant to let him roam on his own and will every few days put him on his harness and leash (watched or he slips out) and sit outside with a close eye. 
The elderly man I received him from was giving him up due to medical issues of his own and could not take him (Mister) where he was going. Mister has no medical issues as I've stated before. He does have a chipped canine, but at this age and point there is nothing to do and it doesn't seem to bother him in the least. I'm not sure what pedigree he is, but I know it is a mix of two purebreds. I have attached a couple photos.