No it wasn't flat, but I have never seen a Swaty that was. It was no more "unflat" than other Swatys though. Unlike yours, the stamping on it is identical to other Swatys. I brought some of my hones to the MN gathering and some of those are on the right side of the table in the second photo from the bottom of
this thread. BTW, Chrisl's hones are on the left side. There are three Swatys in the center of the photo and I'm sure you will be able to pick out which is the 8" Swaty. I have not done much honing with it because I have several Swatys, most of which I am simply stockpiling for young relatives awaiting their first shaves. However, I have honed with it and it cuts just like the others.
I'm glad to hear that you now are also, ahem, well endowed with an 8 incher!