The smell will last several weeks...I did a rifle sling about a month ago and I can still smell the vinegar. ..faint but still there...I've had the smell stay for a very long time on some projects...and on some only a week or two.
I would recommend for your finish, something like Lexol or Montana Pitch Blend over top of your oil.
You might also want to try an acrylic wax, like Mop and Glow mixed 50-50 with water...and no more than 2 light coats...try on scrap leather first to see how you like it.