It's easy to answer your question: We are unable to view our registered items on Apple's Support site.
We used to be able to track our registered products through the Support site, but that facility (with the exception of downloadable software items like QuickTime Pro keys) has been gone for a couple of years now.
Because of this, the best advice is to keep track of your own purchases in case that information is needed by law enforcement agencies (theft), insurance companies (loss) or the IRS (tax itemization) and to not submit this information to Apple, because once it has been submitted, you have little to no control over where it goes or how it is used.