[tlhIngan Hol] {DeSqIv} and {noq}

[De'vID]

I just noticed something odd.

Recently, we were given the noun {noq}, meaning both nipple (anatomy)
and nipple (like on a bottle). The plural is {noqDu'} when referring
to a body part, and {noqmey} when referring to bottles.

In KGT, we were told this about {DeSqIv}:
<A {bargh} is probably the most frequently used pot. It is rather
large and has a flattened bottom. The smaller {nevDagh} is
characterized by its V-shaped handles, termed {DeSqIvDu'} ("elbows";
note that {-Du'}, the plural suffix for body parts, is used here even
though the handles are not literally body parts).>

Previously, some people have taken this to imply that body parts were
a noun class in Klingon, and that body part words take the {-Du'}
suffix even when not referring to a body part. But {noq} seems to
contradict this.

What's going on here? Is one or the other of {noq} or {DeSqIv} an
exception to the rule, and if so, what's the rule? Or does each body
part word work differently when used to refer to a non-body-part in
the plural, and it's just something you have to memorise?

Incidentally, the online version of the qep'a' booklet where {noq} was
given seems to have disappeared:
http://www.kli.org/activities/qepmey/qepa-chamah-wejdich/new-words/

Does anyone have a copy of it?

-- 
De'vID