Headlamp Bucket Diffferences

Thanks to Sean Dezart for three of the images I have posted up here.

I am trying to find out the differences between S30 headlamp buckets, so that I can identify part numbers 63116-N4600 (LH) and 63115-N4600 (RH), which are correct for my late 1977 UK-model 260Z coupe. On my R-Drive fiche, these part numbers are correct for European S30 models from 0/76 on. I do know that the black headlamp bucket in the image below is part number 63116-N4700 (LH), with the corresponding right hand side, part number, 63115-N4700. These (N4700 units) are correct for a 8/76 on 280Z, and have a captive nut (ringed in red in the image) to the second hole back from the front.

I cannot definitively identify the other three variants part numbers in the images below, which respectively have four (no captive nut), three and two holes in the bottom section of the headlamp bucket.  I think these are all metal assemblies.

Any help would be appreciated, thank you.