This is not a perfect answer to your question about Tets, Meg, but I ran a query against the daylily database for tets registered 1958 and earlier, and there are just a small number.
From what I've read, Dr Hamilton Traub of CA was the first to start registering Tets that had been converted from dips. A lot of work on Tets was also done in the early 60's in the Chicago area (why I'm interested in the history).
I also bookmarked some documentation I came across on-line. I'm not sure how it will link for you, but it goes right to a page with "Tetraploids" section on it for me.
https://books.google.com/books...
