PSMSL monthly sea-level data
dataset contains 1214 series of monthly mean sea-level data, from 1 to
183 years long.
I am not sure what the reference is for individual stations: the
geoid or (moving) land. Please consult their web pages.
The dataset is updates once a month from PSMSL. However, PSMSL
depends on the data being sent to them, so the series do not quite
extend to the last month in general.