The answer is no with one exception: the value to a collector will be seriously affected. However, not all antiques have collectors’ interest so there is no high value to lose. Anyone unsure if there is collector’s interest should consult an expert for advice before considering restoration.
All the family favorites we have restored have one purpose with their new life, become functional and look good without having a new look. For these customers the value of the piece becomes priceless.
I should know as I have pieces from both of my grandparents I restored and am using at home on a daily basis. My favorite is my Dad’s quarter sawn oak roll top desk. It was functional, but the finish was deteriorated and soiled. We cleaned off the surface revealing its aged patina, a mellow golden oak. Dad used it daily in his shop office and I recall the times of getting chewed out when I screwed up to sharing a “shot” in celebration when a project was completed better than expected. There is a before and after picture on our web site.
I will not part with the roll top desk, or any of the other pieces at home, because it would be like losing a part of my heritage and memories of the past.