James McIntyre;  This is the video I based my build off of.  The fellow does a great job explaining the build as he goes.
https://www.youtube.com/watch?v=kUbFYDo314E&t=834s
For the knob on the back I just drilled 1/4 inch hole in the end of a 3/4 inch dowel, insert and glue 1/4 -20 nut into the end of the dowel.