MajesticEmu

Well, the screws with spring are very improtant because it adds some pressure on the chip itself. You can try to go to some local shop , see if they aren't selling this screws. It shouldn't be a problem. I did it with my gtx 960 , when i painted it a lost a spring screw, got some from another GPU and it fitted perfectly.

I would even try to contact a seller, if he has these screws. It can happen that he forgot to pack them in the box.

he should ship those to you, thats his fault not your's