First time poster, so forgive me if I'm not aware of forum etiquette here. 
I am starting up a 5e D&D campaign. Actually, converting a few 3e adventures, including Sunless Citadel, Forge of Fury, and Return to the Temple of Elemental Evil to 5e. As I work through it, I'm nerfing a lot of the magic stat modifying weapons and armor that were present in those adventures, based on threads I've seen here and elsewhere discussing the reduced prevalence of stat modifying magic items in 5e.
As I look over the treasure items that are available to the players, I'm trying to figure out a good "curve" at which to distribute treasure. I.e. When would be the earliest I should even consider letting the players see a +1 longsword? What are the balance considerations of having a potion of fire breath? Stuff like that? So far, things are fine, but I'd love some input on how best to deliver the magic.

I am starting up a 5e D&D campaign. Actually, converting a few 3e adventures, including Sunless Citadel, Forge of Fury, and Return to the Temple of Elemental Evil to 5e. As I work through it, I'm nerfing a lot of the magic stat modifying weapons and armor that were present in those adventures, based on threads I've seen here and elsewhere discussing the reduced prevalence of stat modifying magic items in 5e.
As I look over the treasure items that are available to the players, I'm trying to figure out a good "curve" at which to distribute treasure. I.e. When would be the earliest I should even consider letting the players see a +1 longsword? What are the balance considerations of having a potion of fire breath? Stuff like that? So far, things are fine, but I'd love some input on how best to deliver the magic.