The only "drop" in blade in plain edge will be from a Sideclip. You may have to file the back to accommodate the locking mechanism and add a small notch at the bottom of the blade for the locking mechanism pivot. It can be done, but will take time and careful measuring. Finding a Sideclip blade is not easy unless you get a complete tool and swap the blades over. I have asked before in the WTB section and had no replies. Another possibility is to trade the blade with a fellow inmate that wants a serrated blade in the Sideclip. Sideclips are scarce and not cheap.
Pete