You're fine, absolutely. You can even bend them in a little by hand if you want. I've built about 10 using TAPCO flats on a home-made jig (from square tubing) my corners didn't look nearly as nice/sharp as yours.
The reason I mention bending it in by hand is to be sure your FCG pins & selector lever reach far enough over, to engage the right side. You don't want any 'bulges' top to bottom nor front to back
You might want to visit
http://www.akfiles.com/forums/ gunsmithing and Build It Yourself forum. You'll find the answer to every AK question you can think of. Excellent resource, many experienced (50+ completed) builders
Good luck - AK building is ADDICTIVE
Steve in El Paso