I've owned and flown two of these exact J-3Cubs. That's their weak points. I would call Horizn and get some compensation of your choice.

It's an easy fix for all including the cowl. I injected a small amount of Type 2 wood glue through the ultracote directly into the balsa and held in place the correct alignment until glue dried. The cowl I added a small piece of light fiberglass (or you could could CA/micro balls) and used thin CA to adhere it to the cowl. After that dried I added a second thin coat of CA.

They fly fine, but have a strong tendency to drift left on take-off so be prepared to add a strong right rudder to compensate. (Personally I think the engine mounting needs about 2 degrees more right offset.)

My 2 cents. Good luck.