Hey Jerry! Thought I better bump this one for you.
When my dealer swapped the old collars for new, I could see a clear difference. The 'latch' part of the collar was a fair bit wider, to better engage the akas.
The pic below is front and back of an old
collar. "A" is the thin side where the latch first engages, and "B" is the thick side where it actually catches. On measuring the thickness at "B", it looks like 4mm.
On the new collars, the "B" side is considerably thicker, so the 'ramp' A-B is 'steeper'. My guess is ~6mm. When compared side by side, there is no mistaking it.
Unfortunately there don't seem to be any identifying marks etc on them, so you can be sure you have the right ones, other than a visual inspection.
Hope this helps a bit. Maybe if someone (Matt?) can take a pic of the new collars, they could be compared?