Hello Again

I have just been asked to repair a Mitsubishi Light Truck refrigeration unit. The compressor has ceased and I am unable to find a replacement. The refrigeration unit is a Mitsubishi TD21DSL2 unit, running on R404a refrigerant. However, someone fitted a R22 compressor. This has worked fine for some time. But I would like to return the system to it original configuration. The compressor that is in the system at the moment is a Mitsubishi PE2M402MCVA.
Could someone point me in the right direction. By the way I live at the Victoria Falls in Zimbabwe, with no direct access to spares etc.

Many thanks

Errol