Gibbs was a respected provincial gunmaker. The proof marks are metric so the reproof was within the last 20 years. You would want to make sure the chambers were 2-3/4" when the gun was proofed because if the chambers were lengthened afterwards, the gun is no longer in proof. The worn checkering means the gun has seen a lot of use. The Jones underlever is considered a less desirable feature and the gun should consequently cost less than the equivalent top lever gun. To me it is a classic back action hammer gun of very good quality. All purchases of guns of that era are a risk, because any break down can cost you a significant portion of you purchase price. Good luck.
John
