My normal blood pressure is very much dependant on my salt intake. Wheels recipe of 19 gram per kilo salt for bacon is great. Do you add cure #1 on top of the 19 grams?
Robert Goodrick advised me many moons ago to go as low as 17.5% salt plus the cure.
For my personal cured bacon this works out very well, obviously I still have to watch the quantity I eat.
I equilibrium cure everything now and curing times are no longer critical. The longer the better!!
I will be watching all the answers you will get in regard to your fish curing request.