I’m not finding anything. A few references here and there, but no good links or anything with company info. Could they be fronts for or divisions of something else?
My guess is that they are shell companies. Nobody is that invisible. Where could we see public tax records? I wonder if they've ever had a sale that needed sales tax applied, or income for which income tax was due.
Maybe they could get caught by donating so much money with no visible means of having earned it, or paid taxes on it.
Sort of a Al Capone "gotcha!"