Does Refinishing An Antique Reduce Value. It's always a good idea to look for any designer markings on old furniture and to do an Internet search on it before you refinish it. As the basis for this position, people would (and still do) cite the experts on the television show “Antiques Roadshow” on PBS.
If it has a collector's value above ordinary market value of the same kind. It is important to check with an appraiser before you refinish or paint your antique. Ultimately, according to an article in Professional Refinishing Magazine by Peter Cook, a senior producer for Antiques Roadshow, the distinction is less about the type of object and more about its inherent value.
Refinishing a working gun can increase its resale value, but maybe not by as much as what the refinishing cost.
A refinished antique in excellent condition will always be worth less then that, in general terms.
Perhaps you should have it appraised before making a final call. Also, it might be nice to know if the piece even has substantial value as an antique. Sometimes restoring an antique piece can degrade its value.