They had reason to obscure the true origin of these recordings: The Cold War was still in full force, and the stench of the McCarthy era was still there even though he himself was brought down the prior year. No doubt the people running Urania didn't want to see themselves on the receiving end of a Congressional investigation into supposed Communist sympathies. (It was for the same reasons, when Gene Deitch directed the 13 Tom & Jerry cartoons for MGM in 1961-62, that certain names were toyed around with - as they were made behind the Soviet bloc in Prague, Czechoslovakia.)
FWIW, the stamped matrix numbers are XTV22459-1B. and XTV22573-1A. Note the 'high fidelity' frequency range touted as "50~ - 15,000~" (hertz).
IINM, the recordings are from DDR (East Germany): the Berlin Symphony Orchestra was based in the Soviet zone. The anonymous liner notes don't make that clear.