"How does the DCI-P3 colour space of the PANASONIC BT-4LH310 LCD PRODUCTION MONITOR relate to the colour spaces we commonly refer to in photographic use? (sRBG, Adobe RGB or Pro-photo RGB) In other words I am trying to ask 'What would I see in photographic terms on this monitor? in terms of colour gamut?'
I would guess pretty much what you are already getting. There is no comparison in layman's terms, and mathematical comparisons don't translate into real-world technology. Hence the importance of gamuts over color spaces.
This is the simplest explanation I can give:
Movies under the DCI specification (there are many others, but DCI is what the big studios Hollywood use) are encoded in the CIE XYZ color space (which basically translates to "the best theoretical space possible" - I interpret it as "whatever color space I want it to be"). CIE XYZ in layman's terms is the color space of the eye, based on CIE 1931, and which is still being revised as far as I know.
Projectors use different display technologies (DLP being the most common for theatrical display) than LEDs/LCDs/Plasma, etc. A movie, even though is supposed to be in CIE XYZ (smoke and mirrors), is usually conformed to what the projector can display, which is DCI-P3. It is the projector equivalent of sRGB (Computer displays) and BTU Rec.609 (HDTV). A post production studio for movies will need to work in this space because they too will have projectors for mastering.
The fact that the Panasonic 4K monitor is "96%" of DCI-P3 tells me the technology is similar to computer monitors (99% AdobeRGB), and nothing else. But sRGB and AdobeRGB will still exist, along with Rec. 609 (sRGB for all practical considerations).
...I was unable to find on Google how the DCI-P3 color space TRANSLATES into terms that I understand: is it an sRGB, an Adobe RBG or somewhere in-between, or wider colour gamut? Google only tells me (as you have pointed out) what the DCI-P3 color space (and therefore this particular monitor) means in terms of video, something I (and surely this part of the forum) have no interest in at all.
The answer to your question is of no interest to you either, because the answer is purely technical. It's the equivalent of asking "How does B&W and color TRANSLATE?"
The answer above is the best "translation" you're going to get without getting into the math.
If this monitor is a stable and wide gamut (Adobe RGB or higher) screen, then its exciting news; check out its size and resolution: 31-inch 4096 x 2160! Something like this is what I would like to have to see my D800 sourced 1.3 gig Pro-photo (stitched) 16 bit tiff files, which are then printed out on my 9700, so that I could get the best colour on my prints as possible. Would you agree?
I'm not answering for Jeff, but why not wait until the monitors are shipping and tested in practical terms? In theory though, I believe these monitors will be as capable as the high-end prosumer models from Eizo and NEC - i.e., they will do 99% Adobe RGB.
Whether or not they will give 'you' the 'best' color on 'your' prints, not even Panasonic can answer.