Making a flip front end

I use ultra fine saw blades to do micro surgery to my builds.

https://www.micromark.com/product/2366

  One could carefully scribe through the fender lines with a scribe tool or the back of a #11 ( standard) x-acto blade. You will have to glue the hood down first as that will align everything.

  As for hinges, hollow stock and solid round stock, located behind and beneath the grill area. Mount the round stck to the frame extentiond where your front bumper would attach and BOOM Bob's your uncle.

There are saws now getting popular that have a very thin blade with photo-etched teeth (no clearance angle) that should do the job.  Try google search for something like PE razor saw.

Because there is virtually no kerf, these saws really drag when cutting plastic.  I lubricate the blade with just water, and it works fine, with no oily residue left on the plastic.  Speeds up the sawing.