Lost my battery hold down.

The metal hold-downs usually quickly rusted, even the "improved" plastic-coated ones, probably from the combination of stray battery fluid, sulfur fumes, and stray ground currents. I used an all-rubber one on one of my old Mopars, from an auto parts. Time will tell how that lasts. BTW, to protect your metal battery tray try putting a "Battery Mat" underneath (ebay) like I did in all my cars. It has chemicals which neutralize any dribbling battery fluids. Of course a totally sealed gel battery also works (Optima, Autozone Platinum).