After working almost 50 years in the field of conservation, and having had the privilege of working with hundreds of nationally significant objects for many major institutions, I feel somewhat qualified to make some comments on the field. First of all the conservator is not a historian or curator but a materials scientist. They should be trained in materials science so they understand the chemical and physical parameters of every material they work with. This includes, not only the object itself, but every material or substance that came in contact with the object in the past, and what it will be in contact with during their treatment, and in the future. The conservators first responsibility is to determine the level of deterioration, what the possible causes were and how to stabilize the object to mitigate future deterioration. Restoration is secondary and in most cases not in the best interest of the object.
The professional standards for the profession are set by the American Institute of Conservation (AIC) and they include a strict Code of Ethics. A Conservation cannot collect, buy, sell or trade in the area of their expertise. The intimate knowledge they gain in working with documented works enables them capable of producing fakes or forgeries. Treatments must be reversible and thoroughly documented. If an object is to have an extended life span it will pass thru many owners and have many conservation treatments so the less done the better. Proper conditions for display, handling and storage are a must if an object is to survive. All evidence of the objects history and use, including the particulate matter, should be sampled, identified, recorded and not removed unless it is causing active deterioration of the object.
If one truly treasures the objects they collect, they will familiarize themselves with the requirements of proper care and make sure any treatment to the object is minimal and carried out by a qualified professional. The AIC maintains a website where one can find a conservator and check out their qualifications.
I can honestly say, the most serious damage I have seen to objects has been caused by previous treatments. This includes the Star Spangled Banner where the manner of stitching of the previous treatment was stressing and deteriorating the fabrics. If you truly treasure these object you are studying and collecting, take some time to familiarize yourself with the requirements for their preservation and maintain accurate documentation so they will be preserved and improved not destroyed by your stewardship.