This unit is rather rough around the edges. The case is falling apart on the back side and the covering is coming off but despite some light surface rust on the unit it seems to working fine and performing well. The roll chart still moves ok, The Line adjust lines up when pressed and I tested a couple 12ax7s on the unit and the results compared closely with my 600a. That being said I’m sure that it could use a calibration after all the years in storage. I brought it up on a variac and left it on for about an hour to make sure it was stable and it seems ok but I cannot guarantee future use so it is being sold as is.