A few years ago there was a guy who refurbished vintage Marantz receivers and sold them on eBay. I think is seller name was SSTK or something like that. I'm pretty sure he offers some sort of warranty. If I'm not mistaking, he had a few of his receivers used as show pieces by Marantz.
His prices were a little higher than others, but not too much. Hopefully you get what you pay for with his work. I haven't bought one from him, but a friend on another forum did and he was very happy with it. He said that people who didn't know about them thought it was a brand new receiver.
I have no connection to the seller. Just throwing an idea out there if you're serious about buying a vintage Marantz.
His prices were a little higher than others, but not too much. Hopefully you get what you pay for with his work. I haven't bought one from him, but a friend on another forum did and he was very happy with it. He said that people who didn't know about them thought it was a brand new receiver.
I have no connection to the seller. Just throwing an idea out there if you're serious about buying a vintage Marantz.