I took the v6 flywheel and the mercedes flywheel to a machinist.  He scanned the bolt pattern and center hole of the mercedes flywheel and uploaded to his computer.  He used a cnc mill to do the cuts.  The center hole was bored out to match the mercedes crank flange and the bolt holes were very slightly slotted probably only 1mm.  He also removed the toyota ring gear and cut the outer diameter to a press fit for the mercedes ring gear to be used.  This allows me to use the mercedes starter without further modifications.  It runs smooth and the starter engages properly.  It was well worth the money to pay for this machine work.  I did make the adapter ring with a lathe to fit the toyota pilot bearing.  This was relatively easy with a manual lathe.
Sorry for the delayed response, I haven't been on in a while.  Hope this helps