I finally came across the elusive thread discussing changes to the objective ends of the SV EL.
Here is the post that I was thinking of that shows the cut-away photos of the two binoculars .....
http://www.birdforum.net/showpost.php?p=3191981&postcount=58
Here is a following post in that same thread where Dr. Gijs Van Ginkel says the following about the above photo he posted .....
http://www.birdforum.net/showpost.php?p=3192174&postcount=62
...... The top image shows, as I mentioned, an early production of a 42 mm Swar. SV and what is striking in comparison with the later production in the picture below is the difference in the objective construction.
The objective lenses in the latest SV production are deeper into the binocular body, which helps as a sun shade. Gijs
That was the comment that indicated to me that there was an ongoing production change. The comment used the words "early production" rather than prototype and went on to state that the objectives in the "latest sv production" are deeper.
However there is a different set of pictures earlier in the thread that look to be of the same cutaways where Gijis says .....
One photo is from the pre production series and the other one is the current SV. There is a big difference in objective built up.
This indicates the top binocular is a prototype and I suspect that post is the basis for Mark's comment.
Assuming the photos are of the same cutaway, it is now confusing to me if the top binocular is a prototype or an early production unit.