Rudy Van Gelder Does Liszt

Yes, Rudy Van Gelder did some recording for Vox in the early 1960s. I have vols.1 and 2 of the Dvorak string quartets by the Kohon quartet of NY University, and there's RVG pressed in the dead wax. The booklet says: mastering: Dr. Rudolph Van Gelder for vol.1, engineer: Dr. Rudolph Van Gelder for vol.2. For the same label, RVG also recorded the Berg string quartet by the same ensemble. If the Liszt was recorded in Vienna (as Liszt's arrangement of the Wanderer Fantasy was), I doubt that Vox flew RVG to Austria to do the job. In this case, RVG in the wax rather means something like: remastered by RVG. But "mastered by RVG" for vol.1 of the Dvorak may mean the same thing.

I have been listening to many RVG Vox classical records (black label with silver writing). They sound rather good: Pergolesi's Stabat Matar, Swan Lake, Mendelsshon's Italian (the latter 2 with Remoortel conducting), Brahms's Rinaldo. What do you think of the recordings? Do they bring a premium?