Monograms kits in the 80's seem to lack that,I usually use Evergreen scale models strips .015x.030,it works perfect but since you have painted your car it may be hard to do without messing the paint.
I'm going to throw in a few more guesses:70' Mercury Cylone,70'oldsmobile Cutlass supreme and lastly a 68'Coronet R/T that will come out first as a Dick Landy Super Stock then later in 2018 as a factory stock version.
A couple more pics of the front end,i used the technique of masking the pentastar with BMF and then using a q-tip lightly dipped in thinner to remove the paint,i think I turned out pretty good.:
Finished this up a couple days ago,a nice Monogram snap kit ,model was painted Tamiya pure white.The taillights don't quite follow the shape of the body though.