Part number for double injection and assemblies

[Willy Tschager]

I love this hobby. I'm authoring part for almost 15 years and still come across things I have no clues about. Given that I read:

http://www.ldraw.org/library/tracker/ref/numberfaq/

I have no idea how to number the top and bottom part of the Animal clam I just fixed:

http://www.ldraw.org/cgi-bin/ptdetail.cgi?s=30218

and how to number the assemblies of the closed and opened version.
(Is it further worth modeling its alias https://rebrickable.com/parts/30218/clam...inner-lip/ or just go with a renumber).

Some goes for double injection:

http://www.ldraw.org/cgi-bin/ptdetail.cg...152c01.dat

how do we number them? Any links in the FAQ?

w.