Instructions for 1961 Buick Special compact wagon Service version show a 1961 front license plate
I checked my model and it has a 1961 front license plate. It also had the custom grille pieces at one time but part of those as well as the stock grille are long lost. Are you casting and chroming those stock grilles you showed or have you just collected them over time? I could use one to restore my old build back to completion. Please email me if you are interested in selling one.
Strangely, your model has a 1962 front license plate. Did AMT change the plate for a second run in 1962 but not change the box art and instructions, or was there a '62 kit version?