Sanyo Ultra Low Freezer Help

Good Day, I need help with a Sanyo Ultra Low freezer that came into the workshop for repairs. The unit uses one compressor and had all its pipes disconnected. I wanted to ask if anyone would have a diagram so I can reconnect the pipes and replace the compressor. The other thing is that it says Refrigerant - Mixed-(Non CFC) ? What gas do I use on this ?
The temperature required is -80 degrees Celsius........
Has anyone worked on these before....
Sanyo Model MDF-192

Many Thanks

Fred

You can download a service manual here https://www.manualslib.com/manual/90...93.html#manual

Thanks Frank, I managed to connect all the pipe and its running and achieving -46 degrees celsius, now am a bit perplexed about the gas to be used. For now, Ive put R290. Would anyone have an idea on what gas I can used to get this fridge down to -85 degrees celsius.

here some refrigerant properties.
http://www.tmt.ugal.ro/crios/Support...I_F09_Ch30.pdf