You may be being too hard on yourself. The in progress pics you posted a while back looked very promising and the fact that you are not yet satisfied with it mean you would probably do it justice if you finished it to your satisfaction. Even if you do not have it cast I
hope you will finish it. The Grand Marquis was a terrific upscale "mainstreamer" of its time and deserves a model. It seems whatever company now has the Crown Vic tooling could turn out a Mercury with minimal investment since many of the CV parts would be usable.