Seconds at 6 rep cases are all too thick because of the thick A7750, gearing and rotor. Anyone who knows Daytonas will spot this on the wrist. Its the one thing I look for when i see a newer Daytona. Also as you already know, the seconds at 6 rep movements are junk. Therefor its impossible to build neither an accurate nor a reliable daytona rep without going to an MBW or Phong case for $1500+
Until the Chinese make a proper movement for the Daytonas, we will be plagued by these two issues. I also want to build an accurate daytona rep, but you around going to need $4000 to do it.
UNLESS you can find one of the older first generation seconds at 6 daytonas because they were a thinner case. Freddy built one of these I believe. They also use an older version of the A7750 that is a low beat 21,600 movement that for some reason doesnt have all the mechanical issues like the newer A7750 seconds at 6. This is your only chance to build anything that at least looks correct.