Look at the motor itself.
Blktop (1994-1997)
Bright Redtop (1991-1992) zenki
Maroon/dark redtop (1992-1993) kouki

About the redtops, it's very odd that nissan used two different color reds. It's my assumption about the redtops years.

Is it possible that the VIN number record was retired and destroyed once it left Japan?
If so, that makes it harder to track down.