Big Al
I'm sorry that you found the bacon a little salty. Usually with this recipe it's the other way around - I've done a calculator for that!
I too would probably increase the sugar and decrease the salt like Dan suggests. My only concern being a tendency for the sugar to 'burn' as the bacon cooks. Gentle cooking should prevent this though.
I've done a calculator for you that reduces the salt from 18.5g to 15g per kg and increases the sugar from 10g to 12g.
Big Al's Cure Calculator
If you settle on a different ration of salt/sugar, just let me know and if it will assist, I will adjust the calculator accordingly.
HTH
Phil