First off, great looking model! That and I had no idea this version of the Matilda existed. I learned something today!
What do you use to edit these things? I have been using tinkercad to edit/change a model for ease of printing but have not done any creating. I am planning on doing a Rolls Royce armo(u)red car turret suitable for the western desert. That open topped turret that was prevalent in 1940-41.
"Nearly all men can stand adversity, but if you want to test a man's character, give him power."