This really boils down to the policy of the publisher. Only about 25% of Publishers allow the use of the Published PDF in institutional repositories. So it's not a matter of finding your article but of finding the allowed version for upload to the DigitalCommons@Molloy.
The post-print is the version which comes after the peer-review process but before the formatting done by the publisher. The content is essentially what is in the published PDF but the visuals are different. The Post-Print is not the same as a Publisher's proof which includes formatting and citation information from the publisher.
The University of Exeter has this example to help clarify the difference.
