I use skinless farmed raised Atlantic salmon, and use the recipe as stated (using the lower times). I do include the tail end, but use less time for the dry brining period.
First I need to ask if you are using kosher (Morton's brand), or did you substitute another salt, and if you used a different salt how much did you use?
If your salmon is thin, you should cut down on the brine times, especially in the first step. So if they came out salty, use a time lower then 7 hours. Also you may have to refresh more then 30 minutes, so after every thirty minutes of refreshing taste, and if too salty keep refreshing.