If one of them wasn't, chances are they all weren't. Especially considering one of the people has passed on and it's highly unlikely that person gave the seller their signature rights before passing.
[It's up to the first poster to come up with a set up, and then each following post will either complete it or fill in the blank(s). And, as always, whoever posts the set up is certainly allowed to post their own completion/fill in as a follow up.]