Replacement ground glass improperly installed, 1% of total focusing error.
Taking lens f5.6 Symmar, mount shimmed out 10 mm from lens board.
Viewing lens f4.5 Xenar.
Lens board not flush with front standard at top when installed, 1.5mm error.
A 6.7 mm shim between the view lens mount ring and lens board along with correcting lens board error put focus difference less than 1/2 stop from infinity to 6 foot focused distance.