The big problem with the cost of rebuilding the old radios is the cost of the vacuum tubes. After the advent of the transistor and later the integrated circuit. (IC), vacuum tubes grew out of favor die to the power consumption and the heat generated for all audio equipment. Later, audiophiles determined that the sound quality of vacuum tube amplifiers was far superior to the solid state radios and would only look for vacuum tUbe amplifiers. DUe to the heat generated by the filament and the small confines of a car radio, it is very difficult to dissipate the heat generated. Thus car radio life is not that good, maybe 2-3 years before repair. The limited amount of tubes made each year make the cost high, and also because audiophiles are willing to pay more for a tube the the average person also drives up the cost. As I recall, the vacuum tube that controls the search capability of the WonderBar is a very common tube. But don’t quote me on that because the last time I took my WonderBar apart to fix it was 1969. I replaced it with a AM/FM Cassette stereo on 1970 because I wanted a more modern radio. I did keep my WonderBar in case I ever wanted to put it back in. If it’s not going to be put in shows then I would not worry about it.