Some parts are very expensive and very hard to get for older titles..... i also dont think it wld be very economically friendly to do what your asking.

I am not sure what is meant by "modernize reliability".
Do you mean ramp materials?

Not all TOTAN assembly parts have been reproduced.
Major components such as scoops (reinforced) and ramps have been.
You are going to have to acquire some parts as NOS.
You would have to get a donated wire harness and other general parts from another WPC95 game.
Posts and metal hardware can be purchased from multiple sources.
You will need to go through every assembly and dissect the diagrams.
You will also need to know the game VERY VERY WELL.

Is this possible?
Yes.
Cost effective?
Not necessarily.
It will take months to gather what you need.
You are looking at around $2500+ for the components minimum.

Yes, people have built entire games from parts.
Most were MM, AFM, and MB.

If you are interested in doing procedure this practice on an early SS machine, and do a standard playfield swap with a reproduction including the ground braid.
Stern, Bally, Williams, or Gottlieb.
This is much easier, and straightforward.
You will know if you want to do this ever again.