I got several wills last week at the National Archives. Yes, the National Archives. There is some sort of jurisdictional dispute over the index so unless you have the numbers you have to go there first. They will not copy the index and send it over from the DC Gov. They are there up until about 1870? If you have the number you fill out the request and it will be brought to you in the reading room. I do not know about ordering one by mail. however you can hire someone who does research at the National Archives to get if for you. I did learn the O. S. stands for old series. I have used Marie Malchori CGRS in the past but wanted to make the trip myself. Margaret