You aren't gonna find much on the R16 online, I've looked. The more detailed your search the more helpful it will be like someone said earlier typing in Datsun R16 will bring up datsun results or Nissan R16 and H20 for the H20 you might also add forklift.
Best place would be the roadster sites to find most parts in info on the R16, try 311s.org.