I stand corrected!!!!!!
This evening, I looked at an original 34 Battery Box I had up in the loft.
There are two main straps, one at each end of the box. These straps are formed to hang down and are attached to the outside frame rail at the outboard end and to the center "X" member on the inboard end. There is a third strap that is spot welded to the underside of the main straps. This third strap is bent up 90 deg to form the ends of the battery box. Attached to the vertical part of this third strap is a sheet metal piece to protect the ends of the battery from "Road Debres". A "Battery Hold Down Stud" is also affixed to the top of each end of this third strap.
This third strap does have a ridge formed in it in the portion that is between the two main straps. This Ridge is UP and not down as I had previously posted, but the height of the ridge is no more then the thickness of the main straps. Therefore, when the battery is installed, the battery will rest on the main straps and not on the ridge.
This is sort of long winded and if I had my camera here at home, I would have just taken a picture and posted it.
I hope this helps,
Chris