Pete,
Paradiso Nero IS Acciano. Mario mistakenly started out calling Acciano, "Paradiso Nero". When he visited his family in Italy last summer, apparently, they were quick to set him straight on this fact. Therefore the name Paradiso Nero doesn't apply to any fig Mario has. It was erroneous from the start.
Andy,
Even though it may be slow to get established, it should respond well to fert & lime. So, if you feel yours could take a little fertilizer this spring, then I'd say go for it. Just don't over-do it of course.