The autopsy report gives us the length of the piece of paintbrush that was attached to the ligature (4.5 inches). What were the lengths of the other two pieces?

I don't know for sure about the missing piece, but the part with the bristles is in the photo of the paint tote. Looks like just a couple of inches including the bristles. So far, that would make the paintbrush 6.5 to 7.5" or so. I believe brushes come in standard sizes, so it may be possible to look at the brush and figure out how long it was. Any artists here who can identify what that particular bristle was for and how long it is?