It's hard to be more definitive given the proximity of its issue to the start of the war, which makes it tough to say whether this pattern ended up on the black tunic. As you say, photographic proof is hard to come by of the skull band in wear. But perhaps it was possible towards the end of 1939.
The skull title listed in the 1942 price list issued by the SS-Bekleidungswerke Dachau was probably this pattern. The re-organisation of the Totenkopfverbaende was two years old by that time but it was presumably still available for former members of 'Oberbayern'.
You are most welcome. One of the most rewarding aspects of a hobby is the ability to revisit the same old material for new insights.
Thank you again for the great info Mr D'Alquen !