I have a couple of spare speedo's. However, the needle's are broken off

They aren't hard to change...if you are careful. They just pull off.
In fact, come to think of it I have a speedo that has a broken needle and a noisy gear. But the face plate (with the millage) is perfect. You should be able to transplant the faceplate off it onto yours, providing the gearing is the same (which it should be as it would be easier for Honda to use the same gears and just paint the MPH in the proper needle position, then to use completely different gears).
You can have it for free...just pay the shipping. I don't even want your old one. You can keep it as a spare.
Send me PM if interested?