I just got an awesome birthday present from my parents. A brand new Acme 3 blade for my Supra. It looks like someone used a grinder on one of the blades though. Is this normal or should I take it back?
It is normal. This is part of the finishing process to get the prop within spec. Enjoy your new prop. I am a dealer of the props and see it all the time. My personal prop had the same marks and it works flawlessly.