Thank you kindly for your assistance. Good thinking to use the 45 reissue matrix number.
From: Association for Recorded Sound Discussion List <[log in to unmask]> On Behalf Of Jolyon S Hudson
Sent: Friday, June 14, 2019 3:50 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] "En Mi Viejo San Juan" Victor recording date?
The later 45rpm release [see https://urldefense.proofpoint.com/v2/url?u=http-3A__frontera.library.ucla.edu_recordings_en-2Dmi-2Dviejo-2Dsan-2Djuan-2D15&d=DwIFaQ&c=E2nBno7hEddFhl23N5nD1Q&r=0HnTS5hCIFf-yuHsTjNEfg&m=IGFHcLB0qsn-T5ur7K0RuAsKrTmcNwttpCpoKaNvTEM&s=NnbuLNF6Kt56e_VKDcnu9oze0opBpRf298dMJ9tl1XE&e= ] has the matrix D6XW-2246, I presume RCA Victor carried over the matrix and allocated a new take number for the dubbing.
X = Foreign - Recorded outside U.S.A
W = 7" - 45 RPM - Fine
I think the 78 matrix may therefore have been D6XB-2246 with the B = 10"
D6XB-2210 was recorded on 5/23/46
D6XB-2314 was recorded on 6/20/46
So recorded sometime at the end of May beginning of June 1946 I would think. Being in UK I don't have ready access to any files that could get any closer than that.