Virtually every item that is replaced from original diminishes the value of an antique or vintage instrument. The above statement is profoundly correct in my experience, including new holes, drilled or otherwise.
Enormous amounts of items can be repaired if care and time is taken to find the mechanism to do so. Pictures are mandatory to understand the level of work and the various techniques to choose from. Bent tuners can be un-bent, bridges can be repaired and the subtlety of the repair is the most ideal. The slower and more well-thought out the technique; generally the better the result.
Basic functionality should be the goal. The worn nickel or chrome on a bridge is quite secondary; if it is functional within the depth of the period's intonation & adjustment ideal, it's best left as is unless exact & original replacement is possible. A minor bend of a tuning peg does not diminish value nearly as much as an inappropriate replacement.
The closer and sharper the picture & description, the better the suggestion to fit the given problem.