After playing and buying diamonds in this game for 7 years, I also agree it would be a great good will gesture to reward your loyal clients by giving back one of the 3 weapon tier stones they have spent days and dollars making. It is an item that can easily be made, like when the Random Attribute Extraction Stones etc were made and implemented.
If revenue is the concern, the game has many other options where they can make money on diamonds. (For example for GMs , offer new clothes like monthly, as per the original clothing option line available in the game, and the new mount option is a great money maker and appears to have inspired others to offer personal events to raise morale) Another great money making idea is....bring the Overdura Wings back to the Ruby shop (or sell them for like 2000 diamonds) and you can be sure most people on the server will buy them.
I hope the Disassembly/Deviation Stone will come to be.
Thank you and have a nice day/night everyone