I think Don was referring to a 27" 1080p passive Lg monitor. They were sold direct from Korea, not in stores. I was going to buy one back in '14 but I waited too long. I'm glad I didn't make the same mistake on 4K LG's, got two for now but next year I may pick up another one.
Oh, I found the link to the 4K 3D passive screen that I discovered last year. I remember correctly, they were using LG IPS layer part stock but reselling it as THE HAM. There are still a couple on eBay but the seller has 75% feedback and some of the feedback is pretty scary.
So here's the company site: THE HAM
They had several sizes in 3d. The website isn't fully functional either with dead links which makes me think it's a scam by the eBay seller but who knows. Could be legit. I'm guessing they bought up 2015 remaining LED stock and are selling them till they're gone. They have a new line I'd bet the 3D ones are gone other than the eBay listing, unless it's all a scam.
The eBay listing
I think I'd sooner pick up a used LG than risk this, plus you could have customs charge and then if it's broke along the way. But last year I was looking to see if any 4K screens existed with 3D and found this but raised an eyebrow of course.
The Samsung models that do 3D in 4K were Samsung HU8550 and HU9000 series from digging up older posts here, they can display 4k3d half in SbS and maybe top bottom too, not sure. And all 4K LG passive screens but in t/b mode. They'll accept a side by side signal but I believe the vertical resolution is cut in half since it's passive tech.