Hello, new to this, so please bare with me. I am a single young lady who has taken on a huge project. I purchased a 2500 sq ft brick home on a slab & had it moved. Since, I have had to re-do almost everything (learning experience to say the least). I've been living & working on my home for over 2 yrs now & I am embarrassed to say that I have a couple vent covers/registers that I am unable to put up. In moving the house, the roof had to be removed & reconstructed after the move. We re-decked the old roofing flat in an attempt to dry it in, but during the move process I lost most all of my ceilings. So, I hired a buddy of a buddy to install new ceilings (3yrs ago). They did a terrible job at cutting out holes for the vents & missed cutting in some of my electrical connections. I hired an electrician for that part, but I figured I could find a way to hang the vent covers. Now, I can't figure out how to fix them. The drywall cutouts are slightly larger than the metal duct (on either side), and the screws won't fasten. Is there any other way to attach the covers & possibly caulk the small gap?