If the board can be reversible, why not? 
The only wild card is where to position the optional resistor for LocoSound applications. The other consideration is the wiring would be backwards, so that would have to be made clear.
The other oddity is some of the tach boards have a hole in the tang, I'm sure there's a reason for some application. Maybe my universal board would also have the hole, it doesn't appear to affect it's use to replace ones without the hole.
Silkscreened on both sides, the proper sensor and also the corner cut orientation should be added as well.
