Sometimes blossom end rot can be purely internal... paste tomatoes are especially susceptible to it, so that's a distinct possibility. I can't think of anything else that causes that sort of internal blackening (except maybe grey wall, but that affects the vascular tissue of the fruit, not just the seed spaces).

Hope that helps. Congratulations on your success with the Romas.

--Alison

Thanks Alison. I had a little of the typical blossom end rot, but not much. Your theory makes sense. I appreciate your help. Tom