I got this variety from an Italian living in England. They have the typical San Marzano shape but the plants are more compact. While the word Nano can be translated "dwarf" in this case the plants are not dwarf but just compact. Definitely not sprawling. Probably a determinate, tho I didn't pay that much attention to it to be sure.

More info at Tomatobase here   http://tatianastomatobase.com/wiki/San_Marzano_Nano