Apart from one having the tracks on the wrong way around, are these two Shilkas the same variant. I believe these are the examples Hong use for their Iraq 'B' scheme, however Hong show it as an MZ - this doesn't seem to be the case, does it?

http://data3.primeportal.net/apc/michael_rener/zsu-23-4/images/zsu-23-4_17_of_18.jpg

Looks to be the same variant , namely the -4M but without seeing the radar dish unable to tell if it's a -4M3.
It looks like the "Z" in the -4MZ designation is a mistranslation from Cyrillic on the part of Hong and Meng and it is a 3.

Sean

Yes agreed, looks to be a 4M:

http://data3.primeportal.net/apc/michael_rener/zsu-23-4/images/zsu-23-4_03_of_18.jpg

The Hong instructions show that the 2 spades are only fitted to the 4M3 - however this one seems to have the fittings for them:

http://data3.primeportal.net/apc/michael_rener/zsu-23-4/images/zsu-23-4_04_of_18.jpg

Also - the instructions state that this is an Iraqi vehicle..? It looks like Afghanistan to me..?

It is from the Afghan National Army.