Jeff, I hope this attached photo works. Not that I found what you're looking for—this is for concrete pavers—but I wonder if your tile, when laid out, looks something like this.
I've seen a lot of floor tile. Yours isn't common for bathrooms; I wish we had a name for it that could pin it down for you better. It forms an octagon, but there are so many octagonal tiles that turn up that are nothing like what you have, so just searching on that isn't much help. (Also, people incorrectly call hexagonal tiles octagonal, so that really messes the results up!)
P.S. Good for you for wanting to match the original.