I have the exact same bike. I’m in agreement that it’s an 84. I’ve had it for about 2 years and I absolutely love it. I’ve changed just about everything on it. But it is just such a great riding bike. You can easily swap the original 27” wheels for 700s. There is plenty of adjustability with the stock cantilevers. I think the secret is that the 610’s had slightly steeper geometry giving them a sportier ride. I’m from NJ, by the coast, and rust is a continuous battle. In Arizona I think a little frame saver or boeshield inside the tubes and you’ll be good for the foreseeable future. You’re going to be very happy with that bike.