Check the following link, S&W did offer a C frame. Based on the article on the model 73, it was also a complete failure.
Smith & Wesson Model 73 - Wikipedia, the free encyclopedia
According to the SCSW, the C-frame was between a J and a K, and only used for the non-cataloged model 73. It was a 6-shot .38 special designed to compete with the Colt Detetive Special.
edit...and scooter123 beat me to it!
The c frame would probably sell well today. I wonder why S&W gave up on them.
I am sending this thread to a friend who is retired from S&W and ask if he knows why S&W dropped the idea. I'll post his reply if he knows about it.