You are looking at the DOOM 5.25" verification (or publication) Master disks. Thanks to some Doom fanatics and John Romero, we now know what these are and I canceled and relisted the auction accordingly. Here's the story.
I purchased these on eBay in 2000 from Robert E. Waring, the author of the Doom strategy guide as a fundraiser for medical bills. A copy, although faded, of that auction is included. Back in the day, the strategy guide needs to be in the store ASAP to sell the book with the game and Robert didn't have the game yet to begin writing. Because of this, Jay Wilbur at iD Software decided to send Robert "the disks that were on his desk." He put a black marker over the words Master Disks and shipped them.
17 years later, assuming these were the original master disks, I listed them for sale on eBay as such. I was invited to a Facebook group and discussed it with DOOM fans, and they tagged John Romero who filled us in on what they are:
"John Romero: The id Software pictures are of the actual original disks that I created. Those id masters were sent to Digital Magnetics to duplicate en masse. But first, they send us a copy of the masters as they will be sent to everyone and I got to install from those masters to check that they are indeed correct dupes. That must be what the person is selling – the verification masters from the duplication company. That is the FIRST second generation set of v1.1 in 5.25" format."
You can see the internal master disks on the iD Software Twitter page by searching for "DOOM Master disks Twitter." It should be the first hit.
A printout of John's post and is also printed out and included to continue the provenance that didn't exist until now.
As you can see, their disks have an iD Software sticker, while these have the DOOM sticker you might be familiar with. So, if I have it right, iD sends the internal master to the duplicator. They make the first copy and send these back to iD to approve. Mr. Romero then says he installed, verified, and approved these making them the only verification, or publication, master discs for the final 1.1 release.
Version 1.1 is the first public registered version of DOOM as shown in numerous wikis.
Well, that was a long story. As mentioned, no one knew these disks even existed making them truly a one-of-a-kind collectible. There were only two masters (internal and publication) and only one official registered 1.1 release, so the odds of seeing the word Master Disk and DOOM again is unlikely.
Thanks again Mr. Romero for clearing up what these were and finally allowing me to establish provenance.