Yes, should be one on both sides of the rudder log, at least there is on mine (Mull F30). I grease it from time to time on no fixed schedule whatsoever. I just look ro see if grease is sort of squeezing out of the top of the log and call it good.
however AI Says
Traditional/Packed Systems: If your rudder tube or housing has a grease nipple (zerk fitting) or a remote grease cap, give it a few shots of marine-grade grease 1 to 2 times per year (or every few months if you use the boat heavily). This helps stop water leaks and keeps things moving smoothly. https://www.facebook.com/groups/Hallberg.Rassy.Club/posts/10158403300733589/