Mounts for a magnum?

You have 2 choices. Modify a factory set of brackets to fit the 360’s different mounting ears or buy a set of Schumacher conversion mounts.

Yup, I get that as implied by the original question, and I'm fine modifying factory mounts, the question is, where do I find them? Are all of the 360 brackets for cars the same, are there specific cars I should look for, is there a part number or source for factory style units etc? As much as they are used, it's crazy how hard of a time I'm having locating a set.