need help to see if my naruto sketches are fake

a buyer opened up a chargeback claiming an akatsuki sketch set was fake. saying the line work and coloring were sloppy. can someone help me authenticate this sketch sequence? https://ibb.co/Xj2YLxp
https://ibb.co/Cv2z0Gc
https://ibb.co/BCFpRmt
https://ibb.co/gZVBFKC
https://ibb.co/KzpFTqG
https://ibb.co/C53WPrX
https://ibb.co/S53ZH7q
https://ibb.co/YhH3hr4

Hi! first off, did you get these from a reputable source originally? I don't know where these are used but the some of the line work looks a bit wobbly imo ( esp feet and the lines of their robes). I'm not sure if they typically use those particular shades of colored pencil for Japanese animation art either. There have been concerns about there being some fake Naruto art going around lately. For example there's someone on ebay who sold some itachi hanken sketches recently and they also have another Itachi sketch for sale and I am personally not sure if they are genuine. If you know the source where the sketches are used I can try to do a comparison in photoshop to help check if they are real. It's definitely a tricky situation and it's a real shame if fakes are going around. Good luck.

i bought it from this ebay seller
https://www.ebay.com/usr/sukeroku_ninja_japan
he said this
"I bought the Akatsuki set and other genga and douga from the same collector.
The collector is a business partner of Naruto's animation production company Studio Pierrot,
who purchases a large amount of Naruto's gengas and douga from Studio Pierrot." "He said he heard when he bought the Akatsuki set from a studio pilot that it was the genga for a promotional anime for one of Naruto's games, the Ultimate series."

oof, potentially bad news then. The ebay seller you listed there is a dropshipper who usually just copies listings off of Yahoo Japan auctions and reposts them to ebay with a hefty upcharge. This does not mean the stuff they sell are all fake but they don't have the items they are selling in hand and could be passing on fake goods without knowing. Hard to believe their claims when they are a dropshipper who doesn't know anything about what they're selling.

thanks for the info, if you have anymore let me know