Looks like your rear brake plate is the steel type which was phased out sometime around 1965/66 in favour of the alloy type which was used on subsequent bikes.
The earlier steel rear brake plates didn't use a grease zerk and instead relied on a squirt of thick oil, the later alloy brake plate did use a zerk fitting. The oil hole on the steel plate was covered by a type of circlip to protect it from dirt and debris. The circlip is part no 65-5674 "Oil hole clip", see This Link
for parts diagram.
I would recommend using a silicone/teflon based high temp brake grease on the brake cam spindle as they are waterproof and much better at lubricating and resistant to drying out.