You can tell it's a twin carb because the air cleaner has 2 wings nut (1 per carb), whereas the stock EA81 has 3. I also may have made some inquiries today

890,000 yen, about $9,300 AUD for the car. Plus your importing costs, taxes etc. Import monster have their own Japanese company so even though it's a domestic only sale IM can purchase domestically and import it for you. Probably up to $14,000 all up, although probably around $13,000 or a bit less with Import Monster. Pre-1989 so you don't need compliance through RAWS, just an engineer or VASS mechanic to inspect and basically say it would have met the ADR's at the time of manufacture. Pre-1985 as well so you can put it on club rego.
The seats are awesome, probably one of the coolest bits on the car. Never seen anything but a stock style interior apart from different dash clusters.