Lehrkind Mansion 

Yes, it's part of that HD.  When you're looking at websites maintained by or somehow in connexion with the owners of contributing properties (or looking at plaques on the properties), you'll often see "listed on the National Register" when they're only contributing properties.  Occasionally you do get individually-listed properties within HDs, such as the Taylor-Zent House in Huntington's North Jefferson Street HD, which I visited the other day; however, these are substantially rarer.  When you see "listed on the National Register" and don't find the property individually listed, you should always look for a surrounding HD, as you did here, before you start to find whether the property got left off.