The Chamberlain is Chamberlaine's Cough Remedy. The older ones were more fully embossed. I've never heard of Moroline before, but I imagine that the one with the bumps is probably older. I don't know why they would switch in the opposite direction.
A lot of the 30's bottles had the "raised bumps" closure. The metal cap had inclined tabs that tightened on the bumps when turned. I dug a dump that was mostly a 30's dump. Many of the bottles had similiar type closures. I think the screw top Morolines are newer. Just my thoughts. Buster