If they were both residents of the state of Ohio at the time of the sale/transfer, then it was a legal private sale/trade. However, if the gun transferred ownership over state lines without an ffl dealer, I suggest you fix that(by taking it to a PA ffl, not OH). Gun trafficking charges are no joke. Either way, there should have been some sort of paperwork, even if it was just an agreement, with a date, on a napkin.
Oh, and next time, read the actual laws.
A person may sell a firearm to an unlicensed resident of his State, if he does not know or have reasonable cause to believe the person is prohibited from receiving or possessing firearms under Federal law. A person may loan or rent a firearm to a resident of any State for temporary use for lawful sporting purposes, if he does not know or have reasonable cause to believe the person is prohibited from receiving or possessing firearms under Federal law. A person may sell or transfer a firearm to a licensee in any State. However, a firearm other than a curio or relic may not be transferred interstate to a licensed collector.
[18 U.S.C. 922(a)(3) and (5), 922(d), 27 CFR 478.29 and 478.30]
A person may only acquire a firearm within the person’s own State, except that he or she may purchase or otherwise acquire a rifle or shotgun, in person, at a licensee's premises in any State, provided the sale complies with State laws applicable in the State of sale and the State where the purchaser resides. A person may borrow or rent a firearm in any State for temporary use for lawful sporting purposes.
[18 U.S.C. 922(a)(3) and (5), 922(b)(3), 27 CFR 478.29 and 478.30]
A person not licensed under the GCA and not prohibited from acquiring firearms may purchase a firearm from an out-of-State source and obtain the firearm if an arrangement is made with a licensed dealer in the purchaser's State of residence for the purchaser to obtain the firearm from the dealer
Hope this helps.