Sometimes the best information comes from the lest expected places. In this case, the first shots of the interior of the Zulfiqar-3 turret came not from a new, public expo or documentary, but from a poor quality, many-year old video that gave us the first images of the Mobarez. In fact, screenshots from the video are frequently seen around the web.
But upon closer examination, a turret belonging to the Zulfiqar-3 can also be observed undergoing some form of work. While it appears to be under construction, there does appear to be some form of camouflage already applied to the exterior which would only indicate a heavy overhaul (since paint schemes are applied at the end of the process, not half-way through.
Regardless, several key features confirm it's identity.
1) Lifting eyes - visible on the lower-right side of the structure
2) Turret ring - visible on top of the structure
3) Gun mount - visible through turret ring. Man in the tan-coat is pointing directly at it and the gun mantlet.
4) Geometry - The turret is turned upside-down and facing away from the camera. The camera is looking at the left-hand turret size with the turret front obscured and the bustle out of view.
Unfortunately, there's not a great deal of information one can discern from the video, thanks in part to the low quality. One thing you can tell however is that I was a but off with my estimate on the location of the turret ring - it's a bit further forward then imagined. While one can see the interior wall of turret, I'm unable to translate this into a worthwhile estimate. However, it is worth noting that you can see the shadow from the turret bottom being cast into the interior wall.