Tom, I grew King Umberto/Humberto/Humbert whatever a few years ago from seeds from a SSE member. Mine had distinct points on the bottom, not sure at this point if they are supposed to be there, but they were mentioned in the yearbook by the member I got seeds from. Others listing have not mentioned points, but say plum shape. Reinhard-Kraft site picture has them as round looking.
I didn't think the flavor was so bad, and would grow Humberto in preference to a small Roma type, with which the fruit are similar to in size. As I remember, it was a very productive plant. Here are what mine looked like -
I grew them when I was looking for the oldest versions of modern tomatoes that I could find, but who knows what changes have crept in through so many years.