Mass Bradley asked "Could you publish a list of your fave OTR sites?"
Thank you for asking, Bradley. There are three sites of particular note for listening to and acquiring new episodes of vintage radio and comedy shows.
One of the oldest is When Radio Was -- a daily offering of shows that air on some radio stations across the country. The radio station I worked for in the late 1980s was one of the first to carry this then-new show. I would listen on radio every night. Then our local station stopped carrying it, and the show moved to the internet. You can also purchase episodes from this company.
The newest site (for me) is OTR Fan -- an internet site that, every day, offers new episodes for download, free. I like this site so much I even donated money to it!
Lastly is this wonderful internet archive that relies on people uploading radio programs to it. They are free to download or listen to online.