I’m coming in here a little late but I thought I’d add a tidbit about the fears of using properly manufactured aluminum push button base. I read some of the previous post and it got me curious so I thought I’d perform a pull test on a GrovTec GTSW-278 rail mount aluminum base using a Chatillon...
Nice work. Another helpful site (though not quite as nice with close-ups like yours) for push button base installation is on you tube: https://www.youtube.com/watch?v=dSl5bahOEDo
Things to remember:
1/2" Forstner bit
9/16 - 18 BOTTOM tap