I have searched most of my accordion literature, both old and modern
norwegian and german publications, some old sovjet accordion books
and old american publications like the one I sent you a snapshot of
earlier. I only find the (R) and (*) symbols in the publications
from Alfred Music in New York. These are single scores with no
editorial. So I have no more sources than what I can google.
Thanks a lot for the details!
Yes, thank you!
In that case, I propose the SMuFL name for the glyph be
accdnClosedSwitchOld, seeing as:
* "CLOSED SWITCH" was said to stand in for the symbol in the one
contemporary explanation found (/Deiro's Royal Method/, 1936), and
* the suffix -Old is well-attested in SMuFL, clueing the user in to a
glyph's obsolescence. (I can't find an example of -Old being used
without there being a non-Old counterpart, but I don't think the absence
of an accdnClosedSwitch glyph will be surprising to any accordion engraver.)
Objections/suggestions/refinements?