I think you did a splendid job with the Mark III.
With regard to the green paint. It is not so much a matter of how much our skills knock us down. It is more important how many times we get up and overcome. You did that and should not concern yourself for a moment. I have had the same thing happen to me more times than I can count, and have had real life experience that tells me there is no such thing as too much dirt, grime, minor battle damage, and weather effects on an armored vehicle or for that matter any vehicle that is in combat. The test is not how pretty. The test is can it still fight.