Sorry of late response.
Unless you know the guy personally to be honest and truthful.
Without verifiable auction you can not be sure what the car's real accidental condition from japan was.
I heard there are paid services available now where you can get the auction sheet with the given engine/chasis no even for more than 3 month old auctions. you can try that.
Other wise test drive it and also get it checked from some good professional mechanic or you can also try "Car Sure" to get it checked.
960,000 seems like an ok price for 28k driven good condition car. but it was me, I would negotiate around 910k .