The question that should be asked, is how a firearm with provisional major repair indicators, found it's way into the system without the marks being removed.
The firearm in question was found to be defective to the extent that it required backloading to a Base Repair Facility...….this means that the repair was beyond the scope of the RAEME attached to the Unit or Inspection Team that identified the fault.
If the repair was beyond the scope of the Base Workshop(highly unlikely) the firearm would be either classified UR, or if it was a receiver problem and replaceable, marked FR and sent to factory where it would have gone through an FTR program.
Once the firearm was repaired by Base Workshops, it would be returned to Unit, if forwarded to Factory, a replacement would be issued to the holding Unit to maintain their holdings.
All paint markings would be removed after either Base Repair or FTR, as the firearm would have been restored to as new condition.(this includes the Cadet paint band)
As this rifle was FTR'd it means that the downgrade to Cadet green was after the FTR date, the further downgrade and marking for Base Repair would have been from the Cadet Unit storage, or possibly about 1980 when the rifles were withdrawn from Cadet Units.
To have survived with the red paint intact is an indicator that the firearm was never repaired...….maybe sold as is with the JJCO purchases.