I think the point that has been made (by those who care) is that even the old stuff will benefit from some upscaling treatment prior to broadcast.
My own view, however, is that the V+ own upscaling abilities should be more than adequate. You don't watch ancient hokum like Randall and Hopkirk (Deceased) for the visual spectacle. In fact, the prospect of Mike Pratt in HD is positively nauseating.
Mind you, there's always Annette Andre ...