For those interested, I've added the upper chamber to the above-referenced 'work in progress.' (I'm done - I certainly don't intend to model the blast damage from the 2005 bombing!)
There doesn't appear to actually be a 'chamber' in there - only internal spiral stairs to the roof deck. It looks like it's completely filled-in stonework (conjecture.) Historically, there was apparently a wooden post-and-roof structure above the deck. (Only the sockets for the posts remain today.)
Model is posted in the SketchUp 3D Warehouse:
http://sketchup.google.com/3dwarehouse/details?mid=de78ece7f12a167c663f954f31de8916
I'm certainly wrong about some of the upper details, but I can't find photos taken from the correct angle - showing the doorway and internal stairs at the top.
Updated Trimble 3DWarehouse URL for the SketchUp model:
https://3dwarehouse.sketchup.com/model/de78ece7f12a167c663f954f31de8916/Malwiya-Tower
Regards,
Taff
Samarra.jpg