I just thought of another thing that may or may not qualify for your research. There exist at both Bayville and New Gretna, New Jersey each a large concrete champagne or wine bottle standing roughly 15 to 20 feet tall. As the Jerseyana goes, these were constructed as an advertising gimick for the Renault winery in South Jersey. These may or may not qualify, but are interesting within themselves. To my knowledge no archaeology has ever been done with these, though it would be interesting to try and develop testable questions with these. Good luck on the remainder of your quest.
Scott Wieczorek