LuckyBlockYoshi I’m guessing this is a Mark V “Female”, due to it lacking the two 6-pounder naval guns, and being armed only with Lewis machine guns. Here is an example of an Mark V “female”:

Slight historical inaccuracy: The Mark V “female” variant was armed with four machine guns on the side pontoons. There are only two on the side of yours.
Huge historical inaccuracy: There was no cannon on the front of any of the “Mark” series of tanks.
Or is this a completely different tank altogether? Or one from your imagination?