From what I get, I think he means the spacing from one sheet of cardstock glued onto the tab, it creates a "upper level", and they arent "even", it's normal. Usually resin covers it, but there are spots only bondo can cover.
Dont forget to go to menards and pick up your respirator for 20-30 dollars, make sure it blocks organic vapors and is niosh approved! Or else.....lung cancer isnt very fun.