I remember seeing a thread where a guy flipped the blank plate over backwards and it made a nice cavity to install a used tach in it he found on eBay. Looked pretty nice.
Not sure you can actually do that. The mounting holes for the tach are offset so i can only be installed oriented 1 way, ditto for the blankoff plate. If you turn it around all 3 of the screw holes wont line up.
