How do you get the gauges to read accurate with the increments on the face?
If you have VDO gauges to work with, the speedo is totally programmable to fit any evenly spaced increments.
The tach is another story, you will be in the ball park.
All the other gauges will require placing the needle onto the spindle when that condition arises. Meaning, you will need external gauges to monitor the conditions then install your needles at that exact position.
I did this on my car and loosely placed the needles so I could take them on and off with ease. Once I was certain they were in the correct position I forced then onto the spindle.