I owned a 1975 Monte Carlo between 1992 to 2001 and fully restored it in that time. (see restoration - Monte Carlo ) I loved that car and sometimes wish I had kept it, but I sold it to get a new 'toy'. Searching I found no 1975 Monte model kits other than NASCAR and felt the amount of work to convert that would be too difficult so I bought 2 Revell SnapTite 77 Montes. I knew I had to correct the front especially so this is all I really did to make this as close as possible.
I cut apart the Revell body and designed a conversion kit to print with my new Elegoo Mars 3d printer. The parts I designed to fit exactly in the spaces cut out and created the bumpers to 'snap' back in as the Revell kit had. I also made a bench seat seeing my car had a bench seat. Test fitted the first version and didn't like it so I tweaked it until I was satisfied.
After a light wet sanding with 1000 grit, I painted a light coat of Tamiya Grey primer, and then airbrushed Molotov Chrome paint on the bumpers. The key is to let this dry with out touching it AT ALL for at least a week. The Molotov will fade a wee bit from handling if you do. This was trial and error for me.
After supergluing (required with resin parts) the body modifications, sanding and cleaning up those areas, I primed the whole body and painted it with MCW Bahama blue metalic paint, exactly like my original car was. Applied bare metal foil on all the chrome trim and painted the grille parts gun metal with a brush. Finally, painted the rubber strips on the front and back bumpers in semi gloss black, while the clear coat dried on the body after foiling.
One trick I use now is I will baremetal foil the tail lights and signal lights and then apply Tamiya, clear amber or clear red over them. This seems to work well for me.
I am very happy with the results. The photoshop image with the car in my driveway really shocked some people and even earned me a banner page image on one of the Facebook model groups I am in.