Having the seller keep a copy of each background check is not realistic. Fires, floods, etc, would cause more issues in the long term. You would need the background check system to keep a history of checks performed to have evidence that someone did not perform a background check. Furthermore, you are suggesting a vast expansion of laws to make all firearms buyers get a carry permit, essentially creating a national registry of permit holders. That does not follow the spirit of the law in the Second Amendment. Your lack of regard for our Constitution and the Bill of Rights would be frowned upon by our founding fathers.
The only possible current background check proposal is that buyer would be responsible to bring a letter of state approval to show the seller. That is similar to the proposal by Senator Coburn.
This would not criminalize the seller for not checking it, but would not keep a felon from getting a firearm. He would simply keep trying sellers until he found one that didn't ask him for the approval letter. This is not a real solution either, and none of these proposals would have prevented Aurora or Newtown, even though the President used references to Newtown repeatedly in discussion about current gun legislation just yesterday. Obama: "Unimaginable" That Congress Would "Defy" Americans And Not Pass Gun Control | RealClearPolitics
How is something proactive if it does not generated the desired and planned results?