Hi RandyF,
welcome you shouldn't be discouraged my your low MPG, i started at low 20s and now im up to around 35, just takes a bit of time and effort.
regarding your question about pre-OBD2 meters have a look at the wiki about meters
Alternative fuel consumption instruments - EcoModder
the preferred one is mpguino, i believe it was developed by people on this forum. They work based on the fuel injector pulses so they can work on any fuel injected car.