How about the probate records? There are a lot more probate records then wills. I was able to find a Smith that way, it does take a lot more work, but you might be able to find something.
There is also an index for the Maryland Genealogical Society books. It's basically the index cut out of each year worth of books, but there could be something there as well.
You might also want to recheck the historical society's files, they do get added to.