While not one of the MLRC portfolio, it was similar in quality.
We worked with a great board member and award-winning modeler to create the base-model grille to convert the '73 back to '71-2 in 3D - wish I'd hoarded a few.
As I recall, the conversion was very straightforward, might have been a day or two all in to get to a master ready to polish. In the end, the roof appeared to have a very slight downward forward rake, which could probably be avoided if someone was to try it again.
IMO, the Revell kit changes everything about that era Mustang, I think a lot of interest will be revived in the subject.