Speedo needle replacement

[FarmerPug]

I have read all of the great guides on splitting a speedo to put in the white dials, but one thing i am not entirely sure about is putting back the needles in place, how do i be sure that when i put the new needles that come with the white dials that they are in the correct place, this is especially important with things like the speedometer needle which needs to be accurate, is there a notch or something just to line it up correctly, or will a more ingenuitive solution need to be used ? i thought of using blu tack to indicate where the needles should rest