Great work Fitz.
The idea for the commander hatch is a good one. The vehicle looks really good.
I was aiming at the Mk III. Will that be next of your production line? The Mk III had the inclined double spring Horstmann suspension which is different. In fact some of the Mk IIAs used the Hosrtmann suspension as well. If you were able to offer on the shopping cart the Mk III body and MK II turret you'd be able to create a variant MK II from the same models. Maybe not perfect but a useful option.
Really impressive stuff thus far.
As an option, a new turret on this would make for an Indian Pattern Mk II. Given that these were used in actual conflict in india that's probably a good option to have or just make a separate model or the option on the shopping cart for the different turret calling this option the Indian pattern version.
Excllent stuff and you have now filled a void in the MK II department!

Happy W