IIRC, Revell/Monogram's earlier Mustangs (93-99) scaled out to 1/24 as well. AMT's were 1/25 and oddly enough they were better kits than the Revell/Monogram versions. Only hardcore American old-schoolers will hate on the Mustang for not being 1/25 scale. Nobody seeing the Mustangs built in person made any comment on scale...it just looks right, no matter what the numbers are.
Sure wish Revell scaled out their imports/compacts/tuners to 1/24
