I needed a new battery and after much searching for batteries recommended in this Forum, I ended up with a Walmart Maxx-124R. It is a near-perfect fit for my '68 280SL's battery tray and hold down bracket and it even has the correct appearance (all black, after the labels easily peel off). If you use Walmart's search tool for finding a new battery, the Maxx-124R does not show up, and the ones that do, don't fit. I took my hold-down bracket to the store to make sure of fit and just happened to find this battery on the shelf. Walmart also has hold-down J-bolts ($3.77) and battery terminal disconnect ($4.97). By the way... this battery has no pick-up straps so you will need one of those that slips over the posts and I had to remove the hood strap and ballast resistor to wiggle it into the tray.
Walmart Part No. Maxx-124R
Cold cranking amps: 700
Crank amps @ 32F: 875
5 year warranty
$98.17