Simple really. Move the missing ebony sources out of Northwind Mine (restoring that to iron in the process) and put them into a new mini-dungeon for the express purpose.
This is *NOT* some kind of rogue balance change - stop listening to the hive on reddit. They have no clue about anything.
When Redbelly Mine was corrected to give the proper type of ore, 3 nodes and 3 loose rocks went unaccounted for. Sources Bethesda very clearly intended to be available to low level characters outside of quest locked locations. Those nodes need to be preserved.
Anyone claiming this isn't the case is actually attempting to convince you to make a preference based balance change to the game which is not what USSEP is about.
If for some reason this solution is not considered acceptable, the only other remaining option will be to put sources in the animal den east of Shor's Stone, under the large rock outcrop.
Under no circumstances is leaving the ebony out of the equation going to be considered.
Issue Data
Issue #33087: Move ebony sources out of Northwind Mine to a new location