hello all jeff groman of classic cycle here. I've identified scotts bike is a custom paramount tandem built for simes and heid. Jack 3 should be able to confirm this. This bike won the 3 mile tandem race in new brunswick nj in the early 50's. the custom tndems sometimes had no serial numbers as they were one offs not franken bikes. I have one of a pair of track tandems (matching) that were built with dual boob tubes. oscar juner had the twin in american cyclery until a few years ago when it was bought by a seattle collector. these are the only two I have seen sans serial number. Ted ernst sent the one i have to me 10 years ago I can dig out photos if any one is interested or scotty mckaskey has photos on the cabe. jeff