Hi Steven,
This post is only an hour old, or so, and I've already been contacted asking to give you credit for our IPDB updates for our Spacelab listings. News travels fast! Except you and I have never communicated. My hunch is that the title you have given this thread, "I discovered the rarest EM pinball machine - IPDB updated w/ findings" implied to the person who contacted me that you and I have communicated about your findings and that I have placed your findings on the IPDB.
I, too, am excited for your discovery but to avoid additional confusion I should gently correct a few things you wrote that could mislead (additional) people.
Quoted from Otaku:
but figured since IPDB finally caught wind of my details, I would share the great story here.
I am unaware of your details. You and I have not communicated until this thread. I do not know about any webpages you may have.
Quoted from Otaku:
(I would've been happy to provide them for use on IPDB if asked, but it appears they contacted the other owner to recreate them all. Haven't heard a peep from them - feel free to reach out...)
You assume I am a regular here on pinside. Ask around. I rarely visit this site so please do not look at it that I am not contacting you. Rather, the IPDB keeps me pretty busy and we rely on our users to contact us with their contributions. That's been the, uh, unspoken social agreement since Day One over 20 years ago that we are a contributor-driven database where folks contact us but indeed I have been wondering if the newer group of hobbyists has flipped that expectation 180 degrees. I do not "hang out" on any pinball site except the IPDB. Not that we are snobs but it is just me there and I am IPDB-centric. In fact, some folks will email me if something is interesting on pinside, then I show up here. That's how I found this thread, because someone emailed me about it.
Quoted from Otaku:
the only 2 known to still exist are owned by me and a gentlemen named Don, who it seems IPDB reached out to for photos after my article (could've called me - I already had billions! ).
Actually, it was Don who emailed ME, with images, in mid-2018, right after we began having our major problem in updating the IPDB. This problem went on for over a year and a lot of work backed-up. Like many other old-timers, I have long been aware of the 30 Spacelabs (we had that number already) but could not do anything about updating our listings. After the problem was over, I was catching up, and Don emailed me again in December 2019 to move forward on this listing update. Now, if Don had become aware of your game to prompt him to email me a reminder, this I do not know. I frequently tell our users to email me a reminder if something they have in motion with me has not yet appeared on the site.
There are many people in the hobby and only one of me, and they each know what games they have while I do not. Pinside members move all around this large website with its thousands of threads while I am a stationary target. So you can see why it's reasonable to ask that our users be the ones to do the reaching out, to me. 
Quoted from Otaku:
As a direct result of my research, a few months later, it is exciting to see the IPDB has now created a brand new page for discovered machine with all of the information I have uncovered, what I deem Spacelab "A", and heavily edited the original page for the "B" model to reflect the change, which is really exciting to me and an honor that I could provide such details:
No, not a direct result of your research, for whatever goodness you have found, sir. As you wrote, you haven't heard a peep out of me. I've never heard of your "A" and "B" designations until this thread and I do not use those terms in our listing update. You and I have not communicated before.
No, not "after your article". Actually, I have had those diagrams for almost two years. Again, we got behind because of our inability to update the IPDB for the longest time (I avoid saying "downtime" as we were full functional for viewing). I am unaware of your article.
Quoted from Otaku:
It was also curious to see IPDB added one thing to my findings, that a knocker was not installed from the factory. But it is
Obviously, then, we did not communicate with you for us to have said that. 
I think what has happened is a coincidence between your research and my updating our listings. Two events that happened in spite of each other and in the same time vicinity that caused you to think I was aware of you. All of my information came from Williams Daily Production Logs and James Loflin's diagrams and from talking with Don about his game, and from a fellow named Ryan.
With apologies, while this is your personal discovery, our listing updates are based almost exclusively on information I have had for two years or more, in addition to my personal knowledge of the Spacelabs from being in the hobby for many years. However, I don't update the IPDB with my personal knowledge until I can back it up. Many of us old-timers know of things that are not on the IPDB because, while they are true, we have only our memories which are anecdotal.
With that said, there are more than two of these games known to exist. Depends on who you know. 
So, I hope this clarifies our wild coincidence to anyone who reads this thread and might assume from it that you and I had been working together to update the IPDB. I have not snubbed you, because you and I have never contacted each other and I have not seen your research.
At your convenience, and if you are willing, please contact us with any pictures (for which you are the photographer) including a good one of the knocker, and also perhaps the schematic you mention that you have. My email address is below (don't post the info here, please).
Thank you,
Jay
IPDB
[email protected]