Son of Vladimir Rosing Richard Rosing has identified this record as copy from Vocalion label that was issued twice in the early 1920s with numbers A0103 and A0203.
This is interesting. But the answer may be more complicated. I have some notes about the connection between this unusual type of record groove, Marathon, and Vocalion. I'll post them here later.
Item 49 in the Vladimir Rosing discography (Record collector, Vol 36 ¹ 3). That is Vocalion. Recorded circa 1920 with acc. the Aeolian Orchestra. Conductor: Guthbert Whitemore. Vocalion catalogue numbers A-0103 and A-0206 (d/s). A 0103 was issued in January 1921. Rosing recorded "Recondita armonia" only one time - for Vocalion. Right speed: probably 82 rpm. Interesting and rare "advance pressing".
But this record is vertically cut! And has raised rings at the edge and centre. No UK Vocalion has these. Also this is 25cm in diameter or a little over, and A-0103 and 0203 are 30cm.
It's very complicated because the MADE IN ENGLAND is in the mirror, as also on Vocalions (but also other types of record before them). Also this unusual type of cut (vertical modulation, but with a narrow groove) was used only for two labels. One is the UK firm Marathon, and the other is US Vocalion before 1920.
It could be a late unpublished Marathon (the company finished in 1916), or an early UK Vocalion recorded with this strange and obsolete cut. But that would have been madness. US Vocalion only used a vertical cut to get around patents that did not apply in England. Non-standard records not playable on normal machines were a guaranteed way to fail.
I am interested in finding a sound file of the Vocalion Recondita Armonia, as I want to check them side by side, in case there's any possibility that one is a re-recording of the other. So far I have found nobody with a copy.