In the context of the technology of the time of manufacture, it would have been well put together from components and materials of very good quality. If Kahles doesn't charge you much for refurbishing it will be worth more than $100 when you get it back. Trace Scope Repair might be able to do it for you, if you get in touch with the man there (Phil) he won't take it on if he doesn't think he can do it, and he does know what he is doing.