Unzip Multipart Zip from Command Line

Thanks in advance for any help. I am trying to unzip a multipart zip file from the command line in OSX 10.8.5.

I created the zip using zip -s 800m foo.zip foo.mov

The file foo.mov is 2.7GB. So I have the files: foo.zip, foo.z01, foo.z02, foo.z03.

I tried using zip -s 0 foo.zip -O foo_unsplit.zip, but then foo_unsplit.zip is only 1.6GB and gives the error below when used with unzip.

error:  invalid compressed data to inflate

I also tried using cat Heritage.zip Heritage.z01 Heritage.z02 Heritage.z03 > Heritage_unsplit.zip but unzipping the result file gives the below result:

unzip Heritage_unsplit.zip Archive:  Heritage_unsplit.zip  End-of-central-directory signature not found.  Either this file is not  a zipfile, or it constitutes one disk of a multi-part archive.  In the  latter case the central directory and zipfile comment will be found on  the last disk(s) of this archive.unzip:  cannot find zipfile directory in one of Heritage_unsplit.zip or        Heritage_unsplit.zip.zip, and cannot find Heritage_unsplit.zip.ZIP, period.

Does anyone know of a way to unzip a multipart file in command line. Have I made a mistake in any of my attempts?