Originally Posted by DiapDealer
Doesn't exist that I know of.
The Kindle will always see your DeDRM'ed copy as a different book in that regard.
I'm not sure that's true, DD. I think Amazon recognise the book from its ASIN identifier, which is not changed by removing the DRM. Eg, you'll still see the popular highlights in a book (if you have that enabled) even with DRM stripped.