Issue with installation holes on Silverllne 38-090

Thanks for contacting us. The screw bosses in the 38-090 are not meant to be threaded, no. You will need to use a screw similar to the 33-073. You could also just try your existing screws. As for the holes in the window not being large enough, I would first confirm that the 38-090 is the right replacement. If you're confident it is, you can try using a rat tail file to widen the holes a hair, or try drilling the holes in the window frame a little larger. Just be careful not to damage the window. I personally don't recall having encountered this problem before when dealing with this lock, which is what made me think that maybe your original was something else.