Alpha Data Trackball

Hi All,

I've got one of these but the left mouse button, of the track ball cover is messed up....it doesn't depress the actual button. I can depress the actual button, if I remove the cover and depress it with my finger.

So, what I wondering is if anyone has a complete unit they'd be will to sell, or the top cover of a unit which no longer works. I'm pretty sure these aren't made anymore., and yes I've searched on the web.

Thanks everyone!!