Hello-I have two copies of Decca 23547 – Siboney and Hasta Manana by bing Crosby with Xavier Cugat.

Both sides have this aberration.

Siboney on the Canadian issue – the MX is L3535B – dating from February 11, 1945
Siboney on the American pressing is WL3535T6B

I am just recording the one with the T and will compare the recordings once recorded.

Does a firm date exist for when Decca started mastering on tape? I have seen this before, but on records that would have preceded the tape process - Mickey