Hello, Tom--
Try the OTRCAT website; they sell mp3s of radio shows
on compact disc. The quality varies from excellent to
barely decipherable, with most shows being in fairly
good shape. I searched their website for "An American
in England" and got the following results.
http://www.otrcat.com/american-england-p-1044.html
http://www.otrcat.com/advanced_search_result.php?keywords=An+American+in+England&osCsid=g1tuivtpjpqsknjriojejj1n32&x=12&y=9
As you may know, Norman Corwin is still healthy and
active at 97 and still teaches in Los Angeles. He's
also active with Peggy Webber's California Artists
Radio Theater. (Leonard Maltin has some recent
pictures of him in the "Leonard's Journal" section of
his website:
http://www.leonardmaltin.com/
All the best--
Randy Skretvedt