If reporting suspicious activity that has occurred at the bank's BRANCH, does the BANK's information go in Part III, items 47 through 63 and the BRANCH's information go in Part III, items 64 through 70?
or have I totally misunderstood the instructions?

You seem to have grasped them quite nicely. And if you are using the discrete filing format, and completed Step 1 before Step 2, you can auto-populate several of the items on the bank by clicking the "yes" button near the top.

Whew! Think I'm losing my mind! We batch file using 3rd party software and it's not putting the data in the correct fields.

And thankfully (having been burnt once before)I'm checking every field and caught it prior to submission.

Thanks for your feedback.

Time to bang on the vendor's door.