Mudcat is a wonderful repository. It takes a little effort to use it that way. Most of the people who post here have learned how to do it, and that it's worth the effort.
1. There are 158 posts listing in the Forum, findable if you search on that term in the big blue box at the top of the forum page. There's a lot of wisdom in those posts.
2. On the search term , there are another 74 in the forum and a bunch of DT songs that come up. There's a lot of wisdom in those posts.
3. On the term there are 9 results. As I mentioned, most Mudcatters use the terms interchageably, so you would want to use that search term as well. There's a lot of wisdom in those posts.
4. Now, MOST of the people who posted all of those are no loner active Mudcatters, and thus will never see your current request. You MAY get answers from a handful of newer members who are still active, but your thread title leads folks to think you want to know the origins of these-- and a lot of folks don't look at origins requests if they can't come up with an answer.
5. The "origins" of zippers and floaters is not, frankly, knowable. They arose before 99.9% of the songs they appear in were ever published. They arose out of memory, going back to who knows where or when.