I haven't seen the article yet since I didn't get my magazine as of
today, but my personal opinion is that the disc material makes not one
whit of difference in how a note sounds.  The sole function of the disc
is to turn the star wheel; the star wheel plucks the tooth; the note
sounds.  There is no interaction of the disc with the comb teeth.
A thin disc, a thick one, a zinc or a steel one -- all they do is turn
the star wheel.

The value/quality of the note that is heard is the product of the
tuning and then the tightness of the case and connection of the comb
to the bedplate to the case.

Nancy Fratti - Nancy Fratti Music Boxes
Canastota, New York, USA
http://www.nancyfrattimusicboxes.com/