Each EMC serial number is registered by EMC, so if you contact your EMC representative, he/she should be able to get more info about this for you, although expansions that were done after the initial install, but weren't registered won't show up. But start by contacting EMC or your reseller and see what you get back. If it appears that your machine is bigger than what you are getting back from EMC, the expansions obviously haven't been registered, but EMC should have Sales Orders somewhere to verify.

Serial numbers do the trick