I think the Colonials used Suett ? I know they stored like Potted meat in those clay pots and put a layer on top , preserved meat over winter ..My refridgeration is a premium on board so ... let eggs warm to room temp. Thin film of petroleum jully and they keep well for a month. Could be more but haven't gone much past it.
As to Eggs in Stores ... do Dominican STORE bought Egg Cartons have the JULIAN Date on them ?
I recall an article a while back that this is the date to look for , forget about SELL date , thats made up.
The Julian date is the key . pick the one with the biggest # . 1- 365 . which would be closest to your calendar Date .
I think its the Law in the US , but not sure about DR ..