Need Help with this one... even Holset is confused

[Phenomenon]

Ok so i picked up this turbo from some old guy in town for free.

Fine and dandy  on free.

It has been 100% rebuilt, repainted and rebalanced... and never run.

Problem is the ding dong took the ID plate off the turbo and has no idea what it came off of originally.

The only number on the entire thing is on the center section... it's either 3500768 or 3500760 or 3500765 or 3600756 or 3600758.... extremely hard to read (see pic below).

It has no internal wastegate and never did... no V-band clamp at all and a split port intake on the exhaust housing.

Anyhow, can someone please tell me what this is?

It's missing a spacer ring, when you put it together the center section drops too far into the exhaust housing and binds the wheels.

Thank you in advance, Gordon

[Phenomenon]

No one has any ideas?

[92CXyD]

No idea, I almost think it is a hybrid of two different Holset groups but not sure.

[Phenomenon]

Beats me, the guy i got it from said it was original but he couldn't remember from what.

It sucks that there is a spacer ring missing though... i want to put this on my 280zx 

[92CXyD]

You may have to take it apart to find out the specs of compressor and turbine.

Then go from there.

The A/R of the turbine housing should be cast in the turbine inlet near the flange.

BTW I love to see this 280zx, I have always wanted one but I can only find really rusted/rotted out ones locally to me.

[Phenomenon]

A pic of my 81 280zx as requested 

[92CXyD]

That looks nice.

When I was just out of high school, a buddy and I use to go rabbit hunting w/ his '79 280zx.

120+mph on a dark road to the lake. We would kill 12 to 15 rabbits on one 5 mile pass.