I know nothing about the original "Highland Homestead" or "PCGNA", having never ordered eggs from either (assuming, for sake of argument, that they are differ. Have drawn my own conclusions about a poster defending them, and the authenticity of the purported Obituary. We are all adults here, confident others can do the same w/o my help.
That said, I do have help to offer in the future.
Every State in this Union has a "Secretary of State", and they ALL have on line business searches, which allow you to find businesses (active or inactive) registered in the State, and often further details - their structure, business address, contact for service of process, often their officers, etc.
This is the link for the MN Secretary of State Business Name Search.
Its not as user friendly as some I've used in the past decades, but it does work. What it does not do, however, is offer evidence that any business name resembling "Highland Homestead", "PCGNA", or "Poultry Conservancy Group of North America" is now, or ever was, a business entity recognized by the State. Unlike many States, MN does not have a separate "dba" (Doing Business As) or Assumed Name" search. However, a bit of digging makes clear that the Business Name search includes not only the traditional Corporate forms (Inc, LLC, partnership, etc) but also those individuals operating under assumed names - click the details of
"Poultry Service Management" as but one example.
As a rule, I don't do business with those not legally recognized by the State in which they operate. Encourage you to do the same.