07-07-2016, 07:38 AM
Welcome to the Phorum Jim. I could not find any repro back sides for the 38-690. Here is an old thread that talks about them. Don't know if any were made.
http://philcoradio.com/phorum/showthread.php?tid=6006
http://philcoradio.com/phorum/showthread.php?tid=6006