pretty sure your "?" is E flat
the push note is D flat, not B

[these notes are intentionally not in the
normal key of the row]

at least that is what it is on the G row
of a GCF 3 row

wle.

Go to link 1 for a comprehensive list of melodeon layouts

If you want proof that accordion players are lazy, check out this link:

http://www.melodeon.net/first_steps.html

also listed above.