Considering that these old machines don't really bring big prices when sold and their value is always subjective, to me, repainting is a non-issue. If you're happy with the appearance and performance of the machine as is, leave it alone. If it needs work, do it. I have seen some absolutely beautiful repainted machines, and will probably paint another one of these days. Green is a lovely color, my son's favorite in fact. Basically, I say, please yourself.