How about this... would this work? Seems cheap ($51, which is not all that cheap, but lower than others I have found), I wonder if its all I would need? It says unloaded brake caliper. I am not concerned about high quality... as long as I can get my car to where I can drive it.

http://www.oreillyauto.com/site/c/detail/A1C4/19778.oap?year=1988&make=Mercedes-Benz&model=300SEL&vi=1194207&partType=03345&parentPartType=C0066



Lastly, are there instructions anywhere as to how to change the rear calipers on these cars?

Thanks