The '68 Impala was modified from the '67 tool, so that should still exist.
The '69-'70 Impala are based on the same tool with the '70 being the last revision. We have the AMT '70 Impala, but where is the MPC version, both hardtop and convertible?
The '71 Impala was an all new tool. Both the hardtop and convertible seemed to be based on the same body tool with just an "insert" to convert the hardtop into the convertible like they did for the '70 Impala.
The '71-'73 body seems to be based on the same tool. With annual updates through '73, that would mean the '71 and '72 would no longer be available for reissue. However, the '73 Caprice should still exist along with the stock front and rear bumpers and hubcaps. Since the '74-'76 Caprice seems to be based on an entirely different body tool, the '73 Caprice should still exist.
According to these assumptions, Round 2 might be able to still reissue these unless the tooling is damaged/destroyed beyond repair.
MPC '68 Impala hardtop and convertible.
MPC '70 Impala hardtop and convertible.
MPC '73 Caprice hardtop.
MPC '71 Impala convertible promo "insert" to make the hardtop into a convertible. However, the ('71 only) trunk "vents" would need to be eliminated to work on a possible '73 Caprice convertible new reissue.