I suppose there's a sliding scale whereby if 'everything' is as it was when manufactured and nothing has been swapped out even for OEM parts then that is the pinnacle, after which any replacement affects value, gradually shedding parts that you'd anticipate might wear out, till the point where you have refinished/modded/replaced main instrument parts and the value is significantly affected. There will come a point where replacing parts might make something a better player/more useable and the value might be slightly higher than if it were stock but unuseable.