The R grind was combined with the TVD series wedge to help with the unique playing conditions found in Japan.  It was available as a limited edition and is sold out.  The only option besides finding someone willing to part with theirs, would be to get a hand ground wedge -  you can get the TVD M,E,V or T and have the leading edge "pre worn" as well as other options.  Here is the link:  http://www.vokey.com/wedgeworks/hand-ground.aspx

I have  a 50 R. I stamped "Magic Stik" on it  for a reason. I'm not sure why this grind isn't available. Proper wedge grind for your game is critical to a great short game. Somedays without my short game I wouldn't have a game. I have mine bent to 52 then go to a 58.09. I'd love to get another 50 R. The grooves are getting worn on my current one. Titleist please bring it back!