I happen to have an F2A (F2 with DP11 finder). Supposedly, the DP1 and DP11 are identical electronically. Before you go to town on your meter, ask yourself several questions. Do you have the tools? Do you have experience working on small delicate complex electromechanical items? Are the CDS meter cells good? Is the ring resistor good? Do you have a known accurate standard to use for calibration? If the meter is inaccurate, the value of something in the circuit has changed. This is most likely one or both CDS cells, the other components are very stable and more easily checked. These (CDS cells) will have to be replaced, or the meter will probably not be able to be calibrated. The cells must be of the correct value, and must be linear from light to dark. The adjustments inside the meter are to compensate for slight differences in the values of new components, not to compensate for badly aged cells. One thing that does sometimes happen is the resistance of the moving arm contacts of the potentiometers will go up due to oxidation over the years, this is easily cured by simply moving the arm and returning it to it's original position. The ring resistor gets jumpy and can be cleaned with a pink pencil eraser, it almost never changes value unless it is badly worn
My meter was professionally serviced before I bought it, it is accurate and I use it according to the instructions, for general and macro photography with the 55/3.5 Micro Nikkor and sometimes extension tubes. These meters use silver oxide cells for power, readily available. For very low light and incident readings I use a LunaPro.