I think that was just on the box art, pretty sure that kit has never had a vinyl top. There is also the convertible version that has been reissued a couple times.
There are vintage, out of production 1/25th scale '71s--the MPC annual and the Johan Sox & Martin drag car, but for cost and availability the R-M kits are the only current choices.
Who knows, Revell may do a '71 version of the new '70 Hemi Cuda kit eventually. Or the aftermarket will do a resin conversion kit for it.