I'm wrapping up the build of my GMV. As you can see in the photo below, there's what looks like a mortar in the bed at the back:

Any ideas as to which mortar it is?
It doesn't look like the M252, which I guess leaves the M224 or the M120 but I'm not sure. Or is it a Carl Gustav? Any help is much appreciated guys
Cheers
Anirudh