Howard Klepper wrote:
Colin S wrote:
I do a fair bit of restoration work on historic instruments, ok not 20th century stuff mainly 19th and 18th century instruments, but the same rules apply.
As Howard said, first do no harm, next if a part still functions leave it alone, replace like with like, but do not try and make new parts look old (this is museum restoration where it should be obvious what is original and what is repair). Do as little as possible to bring the instrument to playable condition.
When I restore a vintage instrument (which is only occasionally) I "age" replacement parts so they look as original as I can get them. I don't know how the museum restoration aesthetic works, and I trust Colin is right about it. But this guitar isn't going into a museum. If I were doing it, I would be trying to match new parts to old.
When doing museum work, do you make replacement parts to the original standard of workmanship (i.e., leaving in saw marks, etc. if that is how it was originally made)? So when you say not to make it look old, what are we talking about? Color & patina? What else?
This is a very interesting area of debate - and from my experience, even within the museam and antiquities environment there is no consensus as to the best approach. Best illustrated by a few examples... In the UK we have the National Trust, that owns historic buildings, gardens and artefacts on behalf of the 'nation' - the debate rages over 'restoration v renovation v conservation'...
To Conserve - basically stabalise item as is - to prevent further deterioration, but now NEW bits added or replaced
To Restore - to stabalise, to replace all broken/damaged parts with original as possible material, to 'recreate' item to as close as possible to how it would have been structurally and visably (caveat this would not include items such as finish patina etc - unless it was say necssary to remove a finish to stabalise parts etc.
To Renovate - to in effect, restore to a condition for USE either original use or new (eg in buildings case, home to offices, or public access rooms etc), new materials/methods could be used if deemed more appropriate, although traditional materials and methods a priority.
In both the restore and Renovate categories, the debate rages on about whether the 'new' or added' material should be 'blended in to create an original look' or simply left so its clear what is non original although material and technique are following the orginal - eg, They might replace a piece of broken sandstone with a new piece of the same material, but will leave the contrast between the new perpect square edges next to a wethered/worn round cornered piece, so everything is clear.
With instruments there is the added dimension that many owners want something playable - so we see nylon strings on old steel string instruments - Is this really any use? afterall the instrument is no longer providing a sound it was designed and crafted to produce? I am not sure I know the answer to that one, but I guess I would probably put on original strings, under no tension and hang it on the wall, yet I can understand the desire to breath at least some life back into these instruments, afterall it was music they were made for, not as wall hangings.... but that's where we will get quite a diverse and equally valid set of opinions

Would be very interested to hear what others think on this... and naturally it a lot could depend on the historic significance of the instrument in question.