Hi.
I remember seeing one at John French's place (JRF Magnetics) and I am sure he would have some info for you regarding the feasibility of maintaining one should you even be starting with a properly functioning machine. In most things it is bad to generalize, but all but put that aside when it comes to the older german audio technology. To extend that to the recording devices, to their top of the line devices, I am sure you can assume that when properly working, they would sound as good as the best you've heard.
Again, you ought to talk to John, he might have more experience with tape machines than anyone in the US.
If I remember correctly, he said that the wearable part of the headstack on those machines was by comparison very thin. At this point in the analog studio situation, any machines is only really worth what the heads are worth. With a machine with worn heads, or in this case even brand new heads, you have to think about replacement cost. I am going to venture that it is really not worth your time or money to get involved unless you need a new child in your life. If you are married or have a girlfriend, you better ask first.
Best.