As far as the 84-89 3.2 goes, Japan received the same motor as the US did...low comp.
Body was the same, thus small bumperette. Not many RHD's though as you might think. But the head lights are focused on the wrong side of the street...RHD.
Post 964, large proportion with Tips.
True many kept in stock. While at the same time, you could go super-radical as always:
www.rauh-welt.com
www.rauh-welt.com/Garraly.html
www.sunburst911.com/top.html
Driving in Japan cities requires straneous stop & go. I had a Supra with steroids and re-built motor every 100K km, or 60K miles. Motor, body, and the car as a whole goes through more stress than the vehicles in the US. can't really tell just by low mileage. having said that however, in general, porsches are relatively kept in good shape.