I just aquired a Stock Turbo from an 89 R32 Skyline - GTS-T (RB20DET) from my brother. He upgraded from stock

ONLY 42,0000 km on it.
Does anyone know what Size Turbo this is and its Trim?
I would like to find a compressor map for this Turbo.
I have heard that ceramic Turbos do not like pressures that exceed 15 PSI. The blades cannot handle it. Is this true?
At what pressure level does this turbo "Run out of breath" or start to REALLY loose efficiency?
How much Power is this Turbo good for? (YES I know this is a POOR question without more info, but I am curious of a ball park HP Number.)
Anything else I should know?
Thanks in advance for the help.