Not sure I understand the "driving out the spacer" issue. I bolted the prop on temporarily, allowing me to remove/reinstall it as many times needed to get the spinner fillers fab'd and riveted to the spinner backplate.
I would not use screws there ... you don't need more screws in the spinner. You'll have 21 #8's attaching the spinner, plus the number you end up with attaching the filler pieces to the spinner. IMO, that's plenty of screws whirling around at 2700rpm.
