I now just take the wheels apart on bikes I have purchased that are 40-50 years old.

often, there are a few spokes that are frozen, so I check the spoke length first, make notes on should the spokes be of a different length.
I am no longer surprised by even factory wheels that were built with the wrong length.
take them apart, clean and polish as bits and rebuild.
all the spokes now are happy, wheel true and tension uniform.