Akai 4000D reel to reel tape recorder

I recently purchased an Akai 4000D reel to reel tape recorder for my collection. It came with eight tapes, as well as the user manual, the original Akai dust cover, and a small bottle of original Akai tape recorder cleaner and brush. The machine works very well, especially after I cleaned the entire tape path, which was very dirty. Two questions I have are: How old is this tape recorder, and should I send it in for a service, or leave it as it is?