When I got my '47 none of the gauges were working and someone had hogged out the radio slot and added some aftermarket gauges.
At the local swap meet a couple weeks ago I found a speedometer of unknown origin that looked like it should fit the hole and got it for $5.
Last night, after much cobbling, I got it grafted into the dash and working!

It even has a couple extra gauges that I will now see if I can make work with my sending units, and idiot lights that I will see about using for turn signal and high-beam indicators (of which I have none).
Pictures of it are here! I'll try to get a photo of it in the dash to post too.