A simple google search and you can verify yourself when detachable carry handles were invented. It is public knowledge, not secret DELTA SEAL team thing.
This is getting silly.
But one more piece of advice, whether you care to believe it or not - SWD did not make BAR, M60 or Tommy Guns, despite what sources may tell you or what you may see on a form or on a receiver.
ETA
Did you ask seller if gun was NIB? He is NOT listing it as NIB. He himself will probably tell it is not the original upper.
Out of curiosity, I would like to learn about this peculiarity. I did a several google searches over the past few days regarding the history or introduction of detachable carry handles and couldn't turn up anything definitive. I did however, come across the invention of MIL-STD-1913 rails and found:
"The rail itself dates from work by the A.R.M.S. company in the early 1980s and Otto Repa in standardizing the Weaver design. Specifications for the M16A2E4 rifle and the M4E1 carbine received type classification generic in December 1994. These were the M16A2 and the M4 modified with new upper receivers where rails replaced hand guards.
The rail is named after the Picatinny Arsenal in New Jersey, USA. The Picatinny Arsenal's role with the rail was to test/evaluate it and to create a military standard for it. This was Mil-STD-1913, dated February 3, 1995."
However, the Picitinny is not the only Rail Interface System.
I believe attherange mentioned in post #8 about an older carry handle. Does this mean the one on this gun is not a Picitinny?
*At this point, I think I will pass on the gun. I am grateful for everyone's input, it has been valuable in helping me make an important decision and what I have learned just in this thread will assist me in future decisions as well (although, I'm sure I will have many more q's). With that said, my inquiries in this thread moving forward are purely for the purpose of edification. To those who have been helpful, but now feel they are beating a dead horse, there is no pressure to provide further answers; know that I appreciate what insight you did provide.