There may be a number of family heirloom tomatoes, which fit this description, especially in Italy. I grew up in NJ, with many Italian friends. They seemed more inclined to save seed than most folk, back then. Around 1970 an Italian friend of my friend, Rocky Mastro, went to visit relatives in Italy. When he returned, he brought seed to a large, indeterminate plum tomato, much larger than most that we know in this country. He commented about it to Rocky, who was an avid gardener. Rocky went over to his home to see the variety, was impressed and got some seed.
In 1973 Rocky shared some seed with my father. We grew it during my teen years. The variety has little disease resistance, but the flavor is extremely intense and pleasant. Unlike Roma, this plum tomato is great served fresh.
In 1983, I was in grad school in Indiana. My wife and I grew a large garden to cut our costs. It was at that time that I became interested in old varieties. I wrote my dad and asked for some seed of Tomato Rocky (the name we gave this variety). He had stopped raising it a few years back. It grew exceedingly well in Indiana. I shared seed through the Seed Savers Exchange and have observed that members who grew/grow it in the upper Midwest have reported the best results with this variety.

Our friend Rocky Mastro passed away, at the age of 83, in 2003. I still maintain this seed, though it really struggles to produce here in OK. Fortunately, Tomato Rocky, as I call it (others simply call it Rocky) has been adopted by a good many people and is even available through some seed companies. I bet your tomato could be related.

Here's a picture of Tomato Rocky:

George
Tahlequah, OK

Hi Mac,

Thanks so much for sharing that information. Interestingly enough, I also acquired the seed in New Jersey, so it could very well be from the same strain. I got if from an 83-year-old friend of mine up in Bergen County, who is also Italian. He has been growing it now for the last 20 years. He sells the seeds to his Italian buddies for $1 a pop:-) I've only grown it for a couple of years, but from what I've experienced, it does seem very disease resistent and thrives here during the hot Jersey summer. Thanks so much for sharing the pic. It looks very similar. I'll take some photos this summer to compare. Best.

George, I would be very interested in growing your Tomato Rocky. I have a few varieties of open pollinated varieties or would be willing to send you a SASE.
I look forward to hearing from you.
Gary