1. You'd be better off posting pics of the gauges for which you're looking. That would be more help to us. First option, call Tim, Parts, 816-524-BASS. He'll be able to tell you if the OEM gauges are available thru Tracker/Nitro. It would help to have the hull number. Second option, pull the gauge and look for details like manufacturer, model #, part #, and call that company to see if they still make the same gauge. Search the Internet [bless Al Gore] for the part. Note that if found used you may find yourself in a few months looking for another replacement. My gauges [2001 versions] look like standard gauges that can be found all over the Internet [once again, I bless you Al Gore]. You could just Yahoo the Internet [it's amazing how often I find myself thanking Al for inventing the Internet] for "marine gauges" and search for yours that way.
2. As to the finder, they've changed a lot in 12 years. Go to the manufacturers website and see if they still make it. Same kind of strategy as above. My boat originally came with a Pro Tracker which was a Humminbird in disguise.
Good luck on your quest.