Can't recall who was asking for photos of some of these guys but here's a few.
Part 1

BT-9B (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

North American BC-1. (U.S. Air Force photo)

BT-14 (U.S. Air Force photo)

North American NJ-1 in flight c 1938 (U.S. Air Force photo)

BT-14 Gunter Field (SDASM archives)

BT-9 (U.S. Air Force photo)

North American BT-9 basic trainer in flight over Randolpf Field.