Do what many do who want quality but no down time of their car. Buy a good used core and send that in ahead of time. Then when its done, spend a hour or so swapping it over and call it a day. Then sell off your old one you removed from your car for the same amount you spent on the core originally to cover your out of pocket expense.
Or...do up a cool ass engine cover with a custom paint job anyway, and I can always do up a snout for you ahead of time and send that polished, fully rebuilt with a refundable core when you send me yours back after you swap that over. I have plenty of GenIII snouts laying around.
~F~