I am in the process of remodeling the first floor of our home which was built in 1907. The picture illustrates insulation installed between the floor joists for a room (that was once a porch from what I can tell) that sits over a crawl space. As you can see, I removed both finish and subfloor down to the joists. As far as insulation goes, I am thinking that I should remove what is there and lay down new batts (I have quite a bit of spare high R-value kraft-faced insulation from another project) with the vapor barrier up (toward the room) and staple the paper to the tops of the joists. The only issue that I see with what is existing is that there are spaces between the batts and the joists. Other than the stains that my own sweat created while removing the original plank subfloor, the insulation looks great (no mold or signs of moisture).
Thanks in advance for your insight,
Well, now, there's what's right and what's right and never the twain shall meet.