WW & Radiator Bottle Question

[72Levi]

I once had a 72 BB parts truck that had the aux battery tray, it had this radiator bottle and bracket on the pass side to hold both ww & radiator bottles. The truck did not have the ww bottle in the bracket when I got it. I know that originally the ww bottle goes on the drivers side with only one bottle. I installed the aux battery tray on the drivers side and want to add the ww bottle in this bracket. The original ww bottle moves around and is not secure in the other bracket. Two questions, is this the original bracket for ww & radiator bottles on BB trucks with aux battery tray on the pass side? If so, which ww bottle goes in there?