After the "Create" action, MenuItem object refers to the created instance, not the one picked in the first loop.
So if you need to copy some settings from that instance into the newly created one, there are two methods:
1. Use a family. Add MenuItem to a family, and then you can do things like "MenuItem Set Items to MenuItemFamily.Items"
2. Use local variables for temporarily storing and copying the values:
Local variable tmpItems
For each MenuItem
set tmpItems to MenuItem.Items
Create MenuItem
MenuItem set Items to tmpItems