When I did my transfer of Walter's 1935 Die Walkure Act I, Ward Marston (a very famous transfer engineer with perfect pitch) criticized it as a little bit sharp in pitch. It was a little bit sharp, because Vienna was using A443. I think most historical reissues are speeded to A440 as a matter of course regardless of the fact that the Vienna, Boston and New York Philharmonics have all used a different tuning standard. So what we hear on CDs may not be totally accurate.