just get what ya need Ben,
the speedo head can be replaced if it doesn't work, the needle is available, and each of the gauges can be individually replaced - if the chrome bezel is pretty ugly, that can be bought alone and not too spendy - make sure the drill is actually driving the unit, need to get into the hole to engage the right thing [I use an end cut off an old cable], and try the drill both directions, I'm thinking it takes the drill in reverse
I could prolly come up w/ a functioning speedo head out of the dozen gauge sets on hand in a pinch
Bill