Futhermore, if I'm paying for the repair, I get to specifiy what I want. Sorry, but I don't want a lecture from my repair guy on the philosophical niceties of invisible repairs - they are excuses for shoddy workmanship - although I'm happy to debate them here.
Glenn
Hi Glenn,
I don't know the case to which you refer, so I will try not jump to any conclusions about the correct or incorrect philosophies of this particular situation.
I can say that when I consider a restoration, it's most usually a conversation concerning expectations, ethics and reality. I am certainly sensitive to what the client wants, but what I believe is best, or ethical, does not always correspond to the client's wishes. I believe clear communication is critical, so I make an effort to assure this is accomplished.
The caveat here is often those who have gone before. There are cases in which approaching "invisible" in an area that has been corrupted by inadvisable repair might require some really invasive work. That's when I slow down to consider the options... one being to decline the work. In other words, a client may specify what they want, but I may not consent to the job.
If performing a restoration, among some other considerations, I wish to accomplish it in the most cosmetically and structurally sound method available, but while disturbing as little of what is original to the piece as possible.
Now, for anyone interested, my background includes working for a conservator (while I was in school), so I have experience on that side of things as well. There are certainly differences in the way a museum conservator approaches an object and how a restorer does, but most good restorers I know have a desire consider this aspect carefully when planning a job. I won't argue or list the variables between the two here, but I will suggest that the goal of museum conservation is not always bring a piece to a usable state, and in the restoration of an instrument outside a museum this is most often the goal.
When restoring a fault, crack or other damage on the corpus of the instrument, there is most usually internal support on the interior... so while the repair may be "not easily detectible from the exterior" does not necessarily make it "not easily detectible". Also, touchup coatings are usually detectible by blacklight. If one wishes to take things further, I suppose access to a CT scanner might come in handy.

Personally, I do think that bow restoration has it's own challenges in terms of ethics. Some of the modern glues leave little trace in a fresh fault, and are difficult to detect even by blacklight (especially when covered by a finish) even though they may not last well during prolonged use. A spline is a good visual way to indicate repair to the tip, and considered to be a viable and reliable repair when accomplished correctly, but it does remove significant original material. Pinning is still the method of choice by some. I suppose a badly battered and/or previously repaired head might be more attractive if it were repaired by grafting new material (to replace the torn up bit), but again, more original to lose. A great replacement frog, if left unmarked, might "pass" in certain circles if it were carried around in ones change pocket for a few months. Still, few argue about the goal accomplishing aesthetic, functional repairs on bows... though there may be some disagreement about just what that means in certain circumstances.
Disclosure is extremely important... but in time (a generation), the accuracy of this disclosure may suffer, or possibly be non-existant. Frankly, I get much more reliable information when I have a chance to look at a dealership's records than I do from the presenting owner (in almost all cases). Detection is simply the most reasonable long-term method to confirm the condition of a piece, but like most things, this is not "foolproof".
Anyway... my 2 cents. Debate on.

PS: Glenn; Are you sure you want this thread on the auction scroll? Let me know if you want it moved.