Welte-Mignon roll 1228 was offered only in the catalogue supplement
(Nachtrag) 1929 N 08-12, and most probably was never sold or rather,
due to the late release, sparsely.  I don't know about a copy.  For
the release see

http://www.welte-mignon.de/cgi-bin/mignon.cgi?action=List%20of%20WELTE%20MIGNON%20Piano% 20Rolls&spracheZumLesen=english

Regards from Freiburg,

Gerhard Dangel
Augustinermuseum, Freiburg
http://www.welte-mignon.de/