I used a combination of buttons on my panels.
The long buttons mounted fine for me with the spacer rings sawn off the bases, as shown
here.
I have found it alot easier to mount the short buttons, and just use a small piece of wood like
this.
The reason the buttons are pushing on the leafswitches in those pictures is that the panels are sitting upside-down on the buttons.
When the buttons aren't pushed, the switches are straight like they should be.
For mounting the short buttons, I just jammed them into the 1-1/8" holes I drilled.
They fit tightly enough that you can't get them back out without working really hard at it.
If there had been a problem, I would have drilled the 1-1/8" halfway through, drilled a hole the rest of the way through that was the size of the threads, and then put the pal nut on them.
I didn't want to do this because I also mounted small lights in the holes with the buttons, and the smaller diameter hole would not have allowed me to do this as easily.