SamOll,
As has been pointed out, finding a replacement sprocket will probably be easier than trying to retrofit the rest of the tank with enough damage to be consistent, which also is likely going to run into the need to add some level of interior detailing, and so on.
On the other hand, since you have expressed a desire to have a go at representing battle damage this may be a good opportunity to practice that skill.
I would also advise taking comments from the group with a grain of salt. While I understand everyone (and, yes, I do mean everyone) is trying in their way to be helpful and get very passionate about their hobby, it's not at all appropriate or necessary to use words like 'foolish' and 'chicanery' to describe an individual's choices with regard to how they go about their hobby, not to mention the idea that there is only one right way to do it. That choice of words sounds more like an attack on you than the constructive input I know it was meant to be.
BTW, If 100% accuracy were in fact the only acceptable outcome I might feel obligated to point out that Gerrymandering is manipulating the boundaries of an electoral constituency so as to favor one party or class, and that jerry rigging (or jury rigging) refers to makeshift repairs or temporary contrivances, made with only the tools and materials that happen to be on hand.