https://law.lis.virginia.gov/vacode/title18.2/chapter7/section18.2-308.2:5/
A. No person shall sell a firearm for money, goods, services or anything else of value unless he has obtained verification from a licensed dealer in firearms that information on the prospective purchaser has been submitted for a criminal history record information check as set out in § 18.2-308.2:2 and that a determination has been received from the Department of State Police that the prospective purchaser is not prohibited under state or federal law from possessing a firearm or such sale is specifically exempted by state or federal law.
Based on that part of the code, the way I read it is "no individual may sell a firearm to another individual without first verifying through a FFL that the buyer is not prohibited from owning firearms".
What it doesn't say is "all transfers must go through an FFL"
So, with that being said, Can I just take another person to a FFL and have the FFL conduct a background check to determine if the person is prohibited or not, without having to put any firearms on the books?
Another example: I buy a firearm from an FFL. I then want to buy a firearm from a private individual the next day. Can that individual contact the FFL, and ask to confirm if I conducted a purchase from their shop, and was the purchase cleared? Would that be sufficient proof that I am not a prohibited person?