Turbo Identification -- Turbo guru help?

[Andy Fong]

I am in Hong Kong now and I found a junk yard on a magazine that they
have some nissan turbos. But they don't know what are they. I personal
didn't see a nissan turbo before, so how can I tell which one is which?
How many nissan stock turbo is out there? I am looking for a T28 Ball
Bearing turbo.  But if they don't have it, I will pick any that fit my
P10. The shocking news is .......... they are HK$1000-$2000 =
~US$150-$280. Since they know what they are, I can probably talk the price
down a bit if I can pretend I know what I am doing.

If someone can give me a nissan stock turbo crush course or the pointer to
the archive, I will really appreciated.

Andy.