John,
The 1954-55 radio is a valuable item because it is rare and because there is no aftermarket radio that fits in the original hole. A non-working truck radio recently sold on eBay for around $400.
The 1953/54 Chevrolet manual tune (not push button) car radio fits in the truck radio's cut-out. The push-btton car radio has a different dial bezel (rounded not rectangular) and it has no speaker mount on the case. This one recently sold for $50 on eBay.
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A reproduction rectangular bezel used to be available but no one seems to sell it now.
By the way, if you use the manual-tune car radio with the speakers not mounted on the case, there is most likely no problem using an after market electric wiper.
Has anyone seen an original electric wiper for sale? At what price? Is a mounting bracket built into the wiper or is it a separate piece (is it a bolt-in replacement for the vacuum motor)?
Tim