Hey, why not? The speedometer will go back into what will amount to be a practically new car anyway (new suspension, new interior, rebuilt engine, new paint job.)
Here it is, before and after
This wasn't as difficult as I thought it would be. At first glance I wondered whether I should attempt it or not. I didn't want to break something and not be able to get it back together and function properly. But, once I studied it a while, I could see how simple the mechanism really is. The only tricky part was figuring out how the "tumblers" work together, so I could back up the numbers in reverse order, without affecting the adjacent ones.
Notice anything else different about the speedometer??? Yes, the needle is bright yellow, like Aaron's "Viper Race Yellow" we are painting the car. It sure makes the needle more visible than the old faded out orange color in its former life. I also painted the pointers on the ammeter, temp. gauge, and fuel gauge. Time well spent for a big improvement.
I don't know if I could explain how to do it verbally, and I'm not about to take it apart again. But if someone has a spare speedometer they can send to me, I would be glad to show step by step with photos. Of course, you can also do like I did and figure it out on your own.
Jerry