This site has a cd of mp3’s of old Nero Wolfe Radio Shows for sale. $5.00 for 27 shows. I assume that is + shipping.
They have one of them, Stamped For Murder, available for download at: http://www.otr-cat.com/otr3/nero_wolfe_501020_stamped_for_murder(otrcat.com).mp3. Please note that the link above will start the mp3 playing. Right click and save linked file as or whatever works for your system to download. This file is 6.7 mb.
I wish they made them available for download rather than on cd. or both. I’d download them now…