I am helping a lady sell her husbands guns in order to donate the money to a church in Africa and one of the guns is a 3rd generation Colt SSA 71/2" bbl 45LC Nickel. It has the box and instructions and according to her husbands last entry into his log book he never shot it and bought it new, but someone has wiped the gun down with some type of solvent and now the nickel is frosted on about 70% of the gun. What kind of value should I put on the gun in order to sell it? Thanks in advance