Bernie has always confused me and I don't know if I would label him an old school leftist... He tried to go down the populist route by picking and choosing some social democracy parts of the Nordic model, like expanding welfare state, but was anti-free trade and wanted to raise corporate income tax which definitely doesn't sit within the definition of the Nordic model.
He had no intention of wealth redistribution proper and overthrowing the means of production - so you can't accurately call him a socialist. I mean, a socialist wouldn't call him a socialist. To a libertarian type, he may be labelled as a socialist, as they define "socialism" differently. In my former libertarian phase, I viewed him as a hard-core socialist - but isn't he just neo-liberalism with the outer appearance of social-democracy to get the populist vote?
He seems like an old school leftist who drifted right all the way over to neo-liberalism. I guess after Clinton turned the Dems into a neo-liberal party he had no choice but to follow this route, as with our Labour Party in the New Labour Tony Blair era.
From the perspective of a national socialist, he's still very confusing, but pretty much a neo-liberal I guess.