Man haven't seen one of those since I sold mine in the mid 80's I remember I bought mine new for like $400 including the case. That guy is a beast, it really belongs in the museum, you gonna get Popeye arms swing that guy.
Good for gold? what coil you have with it?
About the only thing I would buy it for is to hang on the wall in my den. It is cool, but I wouldn't give more than $50.
On old electronic equipment, over time the solders grows spears, and will eventually short it self out. New items soldered with lead free solder will grow the spears at a rate of 2 to 3 time faster than good old lead solder.