question/observation about HTTP/1.1

I am working with a group of printer vendors to define a print protocol 
based on MIME and HTTP.

After reading draft-ietf-http-v11-spec-07, I have a question about
determining lengths of body-parts of a Multipart entity. 

If Content-length is present for a body-part of a Multipart, does it
take precedent over a boundary string?  The section 4.4 'Message Length'
perhaps implies that it does.

Can a 'Transfer-Encoding: chunked' appear in the header of a body-part
of a Multipart entity? 

If the answer to both these questions is yes, then I would like more
explicit wording that the rules for messages applies to nested messages
in Content-types that have nested entities, such as Multipart content-
type.

If the answer is no, then I would like to know if we can change your mind.

Thanks for any help.

Bob Herriot