3 Sets of Data in spreadsheet. How to merge and curate?

I have three sets of data that need to be gracefully merged.

Tab 1: Just 2 columns. Column A is the order from 1 - 80. Column 2 is the structure list.

Tab 2: Export spit out from one of our software systems.
Tab 3: Export spit out from ANOTHER of our software systems.

Tab 4: The hopeful graceful merge.

- Tabs 2 and 3 have... 1) sometimes the same information (easily spotted if they have the same Notification/Notification ID), 2) sometimes they have DIFFERENT information.

- Tab 2 has the information of ONLY the structures that I need. Tab 3 has the information of WAY MORE structures than what I need.

- The structures that are not on Tab 1 (which are only found on tab 3) need to be deleted. I have no use for those structures.

Tab 2 has way more columns than Tab 3. On Tab 4, I have put the columns that I need only, and the last column is all others. As time goes by I will delete those columns as I see or don't see a need for them.

Any help would be greatly appreciated guys. Thanks

I attached the excel spreadsheet.
Any questions, let me know.