If your friends widow is also in NY, contact your local AOMCI group and a wooden boat groups (both are also on facebook and might point you towards locals).
Theres an AOMCI swap meet tomorrow in Edgewood, MD and another in Burnt Hills, NY
APR 29. Someone at either meet might be able to provide a good resource to value or at least SEE some of the vast amount of stuff.. Go to the events link on AOMCIs website, or the local chapters link. There are at least 2 other meets before July up in and around NY.
As a vintage boat owner that prefers vintage motors on vintage boats it would be tragic to wholesale dump anything the family doesnt perceive has having value. As is often the case, they provably dont have any idea what most of it is or what its for, so deciding value would be best left to someone who does know vintage boats and motors.
There could be anything buried in a large collection like that. If they arent in a time crunch to move it all down the road, being patient.
Bob Grubb has a nice Mercury outboard museum, and runs the mid-Pennsylvania KnuckleBusters AOMCI group. He might be helpful dealing w Mercury stuff, and might want Mercury info, brochures and slaes related stuff. He can probably be reached thru the AOMCI site too, or at least the local chapters link. Might even have suggestions about how to deal w a large collection sale, auction or whatever. They've lost a few well known collectors over the last year or so.