Modifying a bass is a rite of passage that most of us go through Kev. In some ways you need to go through it.
The reality is though, that the bridge you already have will be fine, as will be the pickups and the tuners.
But, a Wilkinson bridge will be good too! But then you won't be happy till the tuners match the bridge and so on....
I have an old Aria which I modded, I sprayed all the chrome bits black.
It took me ages, then the paint rubbed off.....
I always wanted EMG pickups, so I simply found some letters out of an old Airfix kit and stuck the letters on. In my head they sounded better..
You will never devalue your first bass mate, you will probably just buy a new one eventually, and then put your Charvette away someplace where you
will rediscover it a few years time, and smile.