Crystal Glass Replacement Knob Set

Have finally figured out why the knobs to my exterior door to front porch keep falling apart: The set screw stem (or bar or whatever it's called) is about 1/2" too short. My 3-1/2 stem is 1/4" on all four sides and as I hope you can see, each knob screws into grooves on either end of the stem. Ho ... (cont.)

Are you able to tell me the door thickness this handle will fit? I am looking to order 20 or more of these handles.

I'm thinking of ordering your Crystal Glass Replacement Knob Set, #43-007, and I'm wondering if you offer backplates with keyholes in satin nickel, also. We have old, probably zinc plated with brass backplates that I've tried to clean up, but I want to either paint over them (a nickel-looking pain ... (cont.)

Do you use barrel screws with your Crystal Glass Replacement parts. If so, do you sell them separately.

Crystal glass replacement knobs with round screws