Same item used to produce various items - how to handle in vantage 6

I have many situtations where I have various versions of a part. For
instance, part #200 may be the same as part #100 but also painted. If
shipping needs part #200 and doesn't have any, he just grabs from part
#100 tells painter to paint and ships them. On the system, we didn't
have any #100 in stock and have not run them under the job yet (which
he shipped against).

How do you transfer inventory from 1 part to use as another part? We
took from #100 to use for #200 and added the operation. Do we create
a job that pulls #100 from inventory then add the operation for paint
and then ship against that job or receive them into inventory under
#200 then ship?

Any suggestions on how to process this would be much appreciated!!!