Have no idea what the correct protocol is for this situation.
Saying that, if Redhill did release his conversions for the P-36 and F8F as MSFS port-over models (for free use to all), and gave full credit to Vertigo Studios in the ReadMe, wouldn't that be ok?
Given that:
* he has made every effort to gain permission, in fact no one seems to have a contact for them
* Vertigo Studio's webpage no longer exists
* The models would be for free use, properly credited
* And their doesn't seem to be anywhere one can but the original aircraft.
Just wondering.