Merrill Denison's radio plays

[Heather Davis-Fisch]

Hello friends, 
I'm casting a wide net and wondering if anyone has information about rights to reproduce/perform Merrill Denison's radio plays. The copy of the plays I've found is the collection Henry Hudson and Other Plays; 6 plays for the microphone from the Romance of Canada series of radio broadcasts - the book is out of print and its publisher is now out of business. I'm hoping for contact information for the Denison estate or, alternately, information about productions of his work within the last 10 years or so that I could track down.  
Thanks in advance, 
Heather