do you have a deck or porch you could meet them on? I have sold many items on CL, from my home. I usually had the item outside (except for the time we sold a treadle!!) Have someone with you, of course. I don't think scammers would target sewing machine sellers. Cash only, of course.
If you don't even want people knowing where you live, then maybe CL is not for you, for something as heavy as a treadle.