Should the same load data be used for coated lead bullets as lubed lead bullets? Or should I use data for same weight jacketed bullets when loading coated lead? I have not found any particular load data for coated lead bullets. If there is any, where can it be found? Thanks!

Yes.

You won't find data for most cast bullets (lubed or coated makes no difference there), and since designs vary so much within the same bullet weight, you'll need to learn how to work up loads for yourself.

Thanks!