Bill,
I am sorry to disagree with you on the statement that, "the 55.5-59 panels all have the 'outer' 2 oval tail lights," but it appears that the outer lights were either with the turn signal option or dealer installed. There was recently a '56 panel on ebay that did not have the outer lights, only the tag light on the left barn door. It appears to be original. You judge. Sorry to muddy the waters.
Les
http://www.flickr.com/photos/our__lives/2527884024/
