Contact the original manufacturer, if your lucky you got a Oly or Bushy. They can apply to the ATF for a variance. Basically, they replace your reciever with a new one. If it's pre-ban, it will maintain it's pre-ban status. I think Bushmaster said it could take up to 6 weeks. Costs about $180.00 from Bushmaster. They do this for damaged(as in you damaged it) and manufacture defects (as in they did it).
I'm gettin ready to try this very route myself, wish me luck.
Broke the trigger guard ear off installing that big roll pin did'nt you? It can happen very easily. Bushmaster offers a assembly video for us kit builders. The production is a bit rough/amatuerish, looks like they did it themselves inhouse, but all the info is there. Worth the investment to me.
I don't know if other manufacturers are offering this or not. Hang in there, I'm sure somebody with more knowledge than me will see this post.