The acid/electrolyte is same. The difference is the chemical make up of the plates in the battery cells, the MF types are a lead calcium alloy while the oldschool is a lead antimony alloy.
The lead calcium batteries also require a higher charging voltage to fully charge. (14.5 - 15V)
You can paint the bracket with a thick primer and also coat it in something like a rubber dip (the dip you see coated on tool handles)