Here's a 30mm flat which I purchased as an unpainted casting from Berliner Zinnfiguren. BZ is pretty sketchy on the details about their third party offerings, but I believe the editor is Tylinski of Berlin. He doesn't maintain an internet presence. Sorry the color tone isn't good on the first photo (and I'm lazy to reshoot it), the second photo gives a better reproduction of it.
With this post, I'm pretty well caught up on the older flats. I have a few recently painted Renaissance flats, not yet photographed.