I have some old Nakamichi equipment (680ZX Cassette, 730 Receiver) in great working condition. Do you know any store(s) that buy used equipment? Any help would be greatly appreciated.
Audio Classics will buy pre owned gear. You can advertise on Audiogon. Or try a forum such as AudioKarma where vintage gear is discussed. Otherwise, place "vintage audio for sale" in a search engine and you'll find individuals who run internet sales out of their house who might buy the equipment.