Not understanding very well your questions but I will try to be accurate...

are you saying that no where in the data is the model numbers that you had before when exporting?
Yes, like I posted... on the spreadsheet AND on the site when you are in frontend there are many of those model numbers, but system is not recognizing those numbers. Like for example: model 002-1009 is there, but system is saying there's no product with model number 002-1009.

The previous upload I did with the other spreadsheet where I discovered the issue this morning is gone because I restored the database afterwards with the backup I had made before the import, so there are nowhere on the db.

Would this answer your questions?