Totally different. The 95-99ish USDM ecus are different from any non US countries due to US OBD-II requirements. Totally different harness connector (white color, more pins), very not compatible with anything else in the world. Hence for the late 90s ECUs from the rest of the world you won't find a USDM equivalent, even with the same engine. In the early 00s Nissan switched to a mostly unified architecture for the ecus and started using similar boxes for every market (with lots exceptions however).
That actually doesn't look too different from the early 90s Nissan ecus. You might check if Micra Pete has worked with that type of ecu and can suggest an existing daughterboard. If there isn't an off the shelf daughterboard available, the processor that runs the engine is probably the 7780 dude on the far left, and the stock ROM is the dude with the yellow sticker. If your lucky, the memory arrangement is similar to other existing 77xx based ecus and making a new daughterboard isn't too bad. I think the 7780 is pretty much pin compatible to the 7790 used in the B13 ecus. I would start by mapping out the memory interface between the 77xx, the external ROM, and the external memory header at the top of the ecu.
Does the car have NATS?