I doubt seriously there were 45's built in 97, BUT, as I mentioned, it's possible one was sold new and rigged on a new 97 model boat. That makes it a 97 motor in many people's eyes. True when working with Honda's anyway.
I'm retired and work on the 40-50 hp motors, as well as the occasional 75's and 90's as a hobby. They are all I work on. A real niche if there ever was one! LOVE bringing them back from the dead and back into productive use. In MY experience, they are ALL very popular with their owners (new and old).
If I were to pick a personal favorite, it would be the pre '05's! They have a REAL choke with choke button, and are much simpler to work on. The '05, '06. and pre fuel injected '07's, all have an automatic electric choke, and I believe they are harder to start.Just like the fuel injected motors, they work great until they don't! At that point they are a vacuum line nightmare, or in the case of the "fuelies" way more complicated (by a factor of about 50) than the earlier motors.
The '05 and later comment my be due to the bolts/fasteners used to assemble the motors. The earlier motors use chrome plated bolts, which some believe are not as strong as the bolts used in the later production motors. I actually prefer the older bolts, as they don't corrode as easily in a salt water environment. As far as the later ones being stronger, you couldn't prove that by me. They'll both break if stuck!
If the motor appears to be in good shape and runs good, there's no reason to be shy of it, especially if it's been used exclusively in fresh water. It uses the same parts the 40's and 50's use (block, head, pistons, rods, carbs, lower units, etc, etc, etc.).
Last, again in my experience, NADA pricing on used Honda outboards is absolutely useless. With the Honda's, it WAY more about finding one for sale, then at a price you can live with.
A nice used 4 stroke (Merc, Yammi, or Honda) in the 40-115 hp range are going to demand a premium just as sure as I'm sitting here. They are just like the proverbial unicorn. If you see one that doesn't have a sky high price on it, it's not going to be around long. Mine seldom last more than a couple of days.... -Al