Bless you, Mark (oder Marcus)!  First, slice and dice:

Mekka muselmannen massen menchen moerder mohren mutter marmor monumenten
macher
Mecca muslims     mass   humans  murder  Moor   mother marble monuments
maker(s
)

Now, when I originally read this, I had not studied any German (despite
a fully German pedigree -- funny how unpopular the language became in
the late '40s and the '50s...).   Now, I am reasonably fluent in it,
and the dratted word does not really parse grammatically.

It's hard to say what's modifying (or trying to modify) what.

It COULD be a gang of marble-monument makers from Mecca who
 1. are muslims and
 2. are mass murderers of Moorish mothers.

Or, it COULD be a gang of Moorish mothers who
 1. are marble-monument makers and
 2. are muslims who are also
 3. mass murderers

Or....  I'll ask a native speaker and see if HE can postulate a
hierarchy of modifiers...

--Thanks again,
     Guy Haas