First time I saw it done was an episode of West Coast Customs at least 10 years ago. Put a 69ish Charger body over a current Charger skate board. Kinda recall them claiming it to be an original idea and wanna say they did a few more times.

Recently stumbled across an instance of somebody putting an 81-83 Mirada body over a modern Charger skate board. Went full on crazy to include narrowing the suspension and doing a lot of custom work to the HVAC box and cowl. It's fully documented start to finish on a youtube channel.

https://www.youtube.com/watch?v=MxQP_0WTT3M