Working on digital gauges for my '66 Dart

Right now this is just in the planning stage - I haven't forgotten about the voltage regulator or ignition module projects. But my '66 Dart has a dead speedometer, my backup speedometer was even deader, and the trunk mounted battery doesn't mix well with the stock ammeter. So I could either track down another speedometer and cross my fingers, get the ammeter converted to a voltmeter professionally, cut up the dash for some completely non-stock looking parts, or find a way to make digital gauges look stock. And I think I'll do the last one. Here is a bad photo editing mock-up of what I'm going for...

digital concept 1.jpg
This leaves a lot intact including the front plastic panel; it only replaces the gauges themselves. The speedometer only lets you see a short "ribbon", so there's no room for digital readouts. The other gauges are a 2" x 0.5" opening that look like I could put a digital readout behind them.