A question for those who have had these in their hands. Do they appear to be OEM parts? 

http://www.ebay.com/itm/Datsun-240Z-280Z-Chrome-headlight-cover-trims/332146172068?_trksid=p2059216.c100149.m2821&_trkparms=ao%3D1%26asc%3D20140127103305%26meid%3D50409c5480114bf49ef82a09540e7b4d%26pid%3D100149%26

Yes, those appear to be the real deal although I know of only one "re-manufacture" and even those were very well done.  I don't know of the "cheap knock-offs" the seller is talking about.  According to Kats, the trim rings came in four different designs.  Here is his sketch.

Thanks Chris, these look like the third example. I think I might try to pick these up. One will have another $300 or so in them once re-plated. I don't plan to go this route as of now, but they will only be harder to find in the future if I do.

Edited March 12, 20178 yr by JLPurcell

3 hours ago, JLPurcell said:

Thanks Chris, these look like the third example. I think I might try to pick these up. One will have another $300 or so in them once re-plated. I don't plan to go this route as of now, but they will only be harder to find in the future if I do.

Hoarder! 

5 hours ago, JSM said:

Hoarder! 

Guilty as charged, but if someone needs them later and I don't change my mind they will be restored and available for trade. JLP

Edited March 12, 20178 yr by JLPurcell