After reading Valky's Horcrux hypothesis, I started to question my own thinking.  

When I first read HBP I didn't think the damage to DD's hand was from the destruction of the Ring Horcrux.  I read it that the damage from DD's hand came from whatever protective magic was guarding the ring (the equivalent of the potion for the locket).  It would make sense there was some type of magic guarding all of Horcruxes (and clearly there is for the Locket).  The diary is hard to say since it appears to have been left in Malfoy's care.

I have always thought the Ring Horcrux is intact when DD comes to Privet Dr and when they go to see Slughorn.  The ring is later gone from DD's office when Harry asks about the mouth-whistle at that point the Horcrux in the ring has been destroyed.  I don't see how the Horcrux could be released from the ring and have the ring still be intact.  I based this assumption on how the diary was destroyed in CoS. Clearly DD was wearing the ring to make a point to Slughorn that DD knew LV had made Horcruxes and had found one. It is quite possible DD already had the altered memory from Slughorn at this point but I don't think so.  

Does anyone think it reads this way or am I misreading it?

Bonnie