It is certainly best to avoid the lowest deck (Marina) on old ships due to vibration and smell etc. You should be O.K. on deck three. She's a nic elittle ship.
Atlantic Deck is deck 3, deck 2 is Marina deck immediately below yours. There does seem to have been several adverse comments about the fuel smell on deck 2. On my last cruise on Braemar I was fortunate to get allocated cabin 4070 in the newly lengthened section. A superior outside twin for sole occupancy. The cabin was lovely with new furniture and fabrics, but the bathroom and shower is on the small size. It was fine for me, but could be a bit claustrophobic for anyone with a large frame. Happy cruising - Jan .