Now that you mention it, it does ring a bell.I posted the details for this a little while ago. A local ebay seller here in UK had this size and the one that usually would fit onto a 42mm PO. It fitted into the bezel nicely. Reason for doing this was that I prefer the thinner numbers on this insert compared to the original insert. I still would prefer an all black background but with the thinner font. I know each to their own.
The inner diameter is a bit larger on that one, is it not, such that there's a bigger gap at the crystal?