I bought my Precision new in 1972 and as was the fashion in my circle of friends, had it repainted several times since.
Recently, since my Jazz is my normal gigger, I sent the old P off to a luthier to have it refinned back to original 3T sunburst. He used Nitro instead of the poly finish that '70s Fenders used. What an amazing difference! The nitro finish has 'opened up' the tone. Its like the car paint had slowly suffocated it and now it can breathe properly again.
If anyone else in considering a refinish, may I heartily recommend a nitrocellulose job. Costs just a little more but makes a significant difference.
I used to sit firmly in the camp of non-believers in all this different finish stuff. Oh how I've changed my song.
This is it before the final refin:
And now: