I have a couple of the Adamas fixed. I plan to attach some 1/4" thick phenolic material to one of them with countersunk flathead screws. I would profile the scales to fit the handle, then router a 1/8" roundover on the outside of them. I think once scales are attached, the factory sheath will not work , as the handle scale location towards the blade will prevent it from seating. This will not be an issue , as I have already made a sheath for it.
Work has me too busy lately to start on it , but I'll post pictures when I get the project done.
The Adamas fixed is one tough knife , and I carry it as an EDC or secondary backup to my main knife , the 162 Bushcrafter.
It makes a great neck knife also by just attaching a lanyard to the bottom of the sheath.