About the Japanese remastering, this much I can tell you:
Lenny/NYPO/DG M2, M9 Japan > Lenny/NYPO/DG M2, M9 USA
Sinopoli/PO/DG M2, M3 Japan > Sinopoli/PO/DG M2, M3 USA
Karajan/BPO/DG M9 (analogue) Japan > Karajan/BPO/DG M9 (analogue) USA & Europe
Levine/Philly/RCA M9 Japan > Levine/Philly/RCA M9 USA
Regards,
John,