I dont want to get into the 60s/70s argument - they were undoubtedly dogs and diamonds in both decades. Its how it plays that matters.
My £0.02 is that its your bass, if you want to mod it, then do so, but be sure and accept that others taste may not be yours, and that you may damage or destroy its value to many people if you do something cosmetically irreversible. If you would not ever let it go to other hands then its up to you what you do. Enough were made in factories that changing yours would make no real difference.
If you [i]might[/i] need the money one day, however reluctantly made the sale would be, then buy a cheap MIM clone of your bass and do the mods to that is my humble advice.