I'm not sure where the guy came up with 5,000 convertibles. The book I have shows total convertible production as follows:
1970 Barracuda:
1970 Six Cylinder Convertibles: 223
1970 Eight Cylinder Convertibles: 1,169
1970 Six Cylinder Grande Coupe Convertibles: 34
1970 Eight Cylinder Grand Coupe Convertibles: 518
1970 Cuda:
1970 Cuda Convertible Eight Cylinder 550
1971 Barracuda:
1971 Six Cylinder Convertibles 132
1971 Eight Cylinder Convertible 721
1971 Cuda:
1971 Eight Cylinder Cuda Convertible: 293