Does this stock tach look ok?(picture included)

[damac]

I have never seen one and luckily didn't have to pay for it. Somebody pried it apart. I have the dash piece as is, a faceplate and a needle that fits on that shaft. Just wondering if this might "look" ok and if its worth the trouble swapping parts to make one good dash.

It looks like there is a tiny wire attached to each of the 3 metal posts, but there is nothing in the 4th hole. Thanks!

http://img.photobucket.com/albums/v44/kellyass/tach.jpg

 

[OLDBULL8]

Three posts, positive, negative 12VDC and a signal. IIRC