back in the day it hade a long tub with a nipple at the end . because of bacteria billed up in the tub , this style of feeder was discontinued in the late 1920s.
the stopper was made so the bottle cud not be refilled . the inside mechanism is missing ,so you can put water in now . I would not try to remove the porcelain stopper.
in the 1930s Pepsi was going threw a transition period , were bottles were using deferent styles . I have seen thee or four deferent bottles with Pepsi embossed on them this I believe Is just another verdant of that time pierhead. I would consider it rear .