Just a pedantic little thing -- as a geomorphology instructor, I can tell you that rivers and coastlines are very, very likely to have changed. Check out pretty much any river mouth in Victoria, Australia, or any island off Maine, US in google earth vs google maps satellite mode for examples of how much they can change inside of just a few years. If something catastrophic has happened (big storm, big earthquake...), huge changes can shift the coastline inside of hours.
If you're going to use geomorphic features for your geocoding, find out what's most stable in your region (keyword search academic journals for geomorphology + your location + change and see what doesn't pop up, or ask a local university geo prof). Vegetated topography can be pretty stable over decades, especially if you only need relative shapes.