You could just carefully disassemble the two covers and put the new cover's guts into the system model front, using its own keypad. You'd still have your system front that way.
If you elect to use the scan front, you'll have to use the radio maintenance program to make that change.
Get the radio's tracking data, edit the tracking data to change it from a system model to a scan model, and write that data to the radio. Then reprogram the radio with programmer, with your regular file,
selecting the scan version of your radio.
Elroy