I heard that one is an "heirloom of heirlooms" type tomato too... very old school tomato genetics!!!
Im sure there are older since tommys come from america and its an Italian heirloom, Cherokee is supposedly 500 years old. Costolutos have a great, bright, acidic flavor with enough juice for sauce while still being firm enough for sandwichs plus their really pretty and the skin isn't overly thick. If you need something rugged Black Plum is your guy they are extremely determined to grow