File the appeal and apply for a concealed carry permit (if possible).
A friend of mine had a delayed background check that went past 30 days and the shop still wouldn't release the firearm to him even though they could. He applied for a permit and after talking with the court clerk found that an arrest when he was 19 or 20 on pot possession was the problem. Since he plead to and was convicted of a misdemeanor 'disturbing the peace' it shouldn't have counted but the arrest was still there. He received his permit and then his firearm within 16 days.
Not sure what your local laws are but if you're clean, qualify, and the permit exempts you from the NICS check it is worth it.