Kelsey Hayes SBP disc brake questions

What EXACTLY is wrong with the set up that your assembling.
I had a hard time trying to figure it all out, and gave up, until my attention span came back.
Why cant the caliper, caliper hose bracket, repop bolts, bolt down onto the spindle?
That bolt is refereed to as a "shoulder bolt" in the industrial world.
Some Kelsey Hays brake engineer, designer, figured that a shoulder bolt was necessary when that system was designed, back in the day.
But in real life a regular 7/16 bolt 1 3/4 inch length will work just fine.
For years and years i thought those shoulder bolts had to be used, as you couldn't find them, so regular grade 8 bolts were used.
Never had an issue using store bought grade 8 bolts of the proper length.
Don't believe me, just get some regular bolts and give it a try, and do it as an experiment.

I never ever, heard of your "issue" dealing with all the disc brake systems that i rebuilt, sold, in the decades that i have done this.
Guess you, have gotta be the first. Dunno.
JV.