If you get a properly restored one are a new one from Either Streetly or MA, then they are very simple to maintain. I provide a set of instructions to my clients specifically written for the machines that come out of my shop. Any technical assistance or support is easily managed over the phone or by email.
From another perspective, the only brand new Mellotron I have ever owned is my M4000. Streetly shipped it to me and the only technician capable of servicing it nearby is me. I have never had to do anything other than clean it and demag the tape heads.
I think that Clay and other Mark VI owners would say the same thing about their machines. If you are going to own one, it doesn't take much to learn how to care for it. It's not a Chevy; you don't have to have a local technician if you get something proper to start with or buy one and have it restored by someone who knows what they are doing. Mellotrons are not wimpy. They are kinda like Harleys and are actually quite hardy and easy to keep running.
Frank (again)
In a message dated 7/25/2010 9:35:58 P.M. Eastern Daylight Time, rmrmax@yahoo.com writes:
There is the risk of shipping and having the know how to make any necessary adjustments when it arrives and to properly service the mellotron or find a competent technician who is capable of doing so.