A friend of mine would always have the recipient show his driver's license for identification, record the number, and have the person complete Form 4473 just like a licensed dealer does.
You then have IDed the person for residency and age, verified the ID by picture and have the person's sworn statement, just as a dealer does, for all the other stuff. You just don't have to ever send it in or have it inspected ....unless it comes time to CYA.