Hi,
Same issue here. The screws for the larger covers were missing. I am assuming that they are not accounted for in the packing list because they are supposed to come screwed into the cover as it is with the smaller covers.
In the instructions, the attachment of the larger covers comes before the installation of the meters. I assumed that the 8 black screws 4-40x3/4" that came in the kit are supposed to hold these covers, and they worked. When I got to the installation of the meters, which are the last to install before moving to wiring and soldering, I noticed that I didn't have any screws for that and realized that those are the ones that I had used on the covers. Luckily, I had some shorter screws available (4-40x3/8"). I swapped those for the black 3/4" screws. The covers are attached securely, so I don't bother switching those out for the correct M3 flavor.
Back to working on the kit...
Cheers,
FS