what brake rod did you use?
on mine I used a stock manual rod and pedal.
I used the 88 MC that was on the vac booster when I converted to manual brakes.
the stock rod is 7" and has a shoulder bolt with o-ring . they do have adjustable rods also.
I will have to take a look at the set up on the bench, it may use the later model rod that has a stud with metal C-clip.
I made my alum plate from 3/8" IIRC, "member tmef" made me up a SS plate that is about thick as a stock plate.
if you remove the vac booster there is a foam gasket pieces that can be used to make a template with to make you own.