I am the Kirst installer.......
The Kirst is a drop in (nothing is drilled and tapped as suggested in the above reply).
You could drill and tap the frame and sountersink a corresponding hole in the Converter ring in the same place that Remington and the various armoury's did in their conversion process (although in the three types done then the plate, which was very thin compared to the Kirst ring, was also dovetailed into the recoil shield). Dovetailing the Kirst is not an option as it is already smaller than the frame window. This whole process is problematic as you have to clear the side of the frame and should also screw the barrel out for access.
Kirst/Strite has made a run of parts to do "thin plate" conversions and they have to be done in house but if this interests you let me know!