I don't think the stacked light units are THAT rare in the US. (Perhaps the corner lights with sockets are more rare) I saw some for sale at the Carlisle PA import flea market last year.
I'm going to hang on to my originals. With 'Miss Daisy', most of the changes that I've done can be put back to how they were before. Besides, if something happened to the Euros....
Maybe I'll drive mostly on the sealed beams but put the Euros on for 'show'.

Happy Motoring, Mark

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DrDKW