Perhaps he should replicate the GTO by Drago aka GTO the breadvan.It featured aerodynamic improvement & noticebly ugly boxy rear end that easily replicated by any means.
& other things that hard to replicate is the front lower contour especially defined by the position of the iconic 3 mouth grill to the front end wheel fender.
But since the GTO is so limited & being stamped on the chassis with odd(?) number to satisfy CIS(nowadays FIA) rules to homoglated the car for World Sportscar Championship Production Class(which need to have atleast 55 road car model or 300 on which the car would running on any given CIS sanctioned world championship events such World Endurances Championship,& Seperated World Championship For Makes) so in the end there not too much car that lying on the road today,& original condition has been scarce & rare due to modification that the Ferrari factory team has made on certain chassis to be eligible with rules(such as longer wheelbase,3.0l engine rules on such.) & this also make birth to SWB(Short WheelBase) & LWB(Long WheelBase).
But still with the homoglation road version quickly snapped by aristocrats & rich & famous during the 60's,that some of them want to be very differents from each other,the original condition of the early car is the most sought-after by collector or auto museum.
There is some GTO's that gone today are custom made by carrozeria Marrazi,GTO By Ghiaa Of Italy,& some has been made as styling exercise by Pinninfarina itself.
Super rare car,lotsa winning,lotsa loopholes being passed,much less has been on the world today explaining why this is the ultimate prestige of Red Pranching horses brand.