O'k, I have figured out how to add to the inventory.
The pinned guide for this has it wrong. It has you adding inventory items under "Non Player Characters > NPC_player"
Changing stats, health, fatigue, magic and adding to inventory in this spot had no effect for me, I suspect that it is just a listing of your original stats and inventory.
To actually add to your inventory you have to go under:
"NPC's Altered/Killed by Player" (Some number will be here)
Then find
"NPCC PlayerSaveGame"
You will find it pulls up the current listing of everything your character has in thier inventory.
To add an item that you do not have simply:
Right click on "NPCC PlayerSaveGame" and chose "Insert Subrecord"
Then pick "NPCO"
It will appear on the bottom of the list, you only have to add what you want. The "..." is a browse it makes picking what you want much easier. And the count is the amount of the items.
You probably already have gold in your inventory. Just change the "count" to whatever amount you want.