Kaisi and Kisubi were definately both male Eastern Lowlands. Easy to tell apart as adults, but less so at this age. Kisubi was longer legged and less squat. Not sure which these photos are of though.
Comparing these two photos with my own photos of the gorillas as adults, I am fairly confident that this is Kaisi. He had very rounded nostrils and his upper lip curved slightly upwards towards his nose.
