As a retired professor for Experimental Particle Physics I am familiar with vacuum tubes and old-fashioned electronics. What would have been closer than making it my hobby to restore technical antiques, like vintage radios, phonographs gramophones and the like. There is hardly any more versatile activity that would keep my 85 years old brain young: getting familiar with the history of an object, trying to fully understand its purpose and provenance, diagnosing its technical and assessing its cosmetic conditions, and evaluating steps to improve them. Then comes the restoration, as soft and non-invasive as possible, testing the results, taking pictures, writing descriptions and documenting all that. The final steps are pricing the object and making it ready for sale, including careful packing and shipping. You are also kindly invited to visit us in Chilliwack, B.C. Canada.