#4, That looks like a '66 Galaxie in the second picture, but I guess rebodying the same chassis was common after wrecks.
Interestingly... I was looking up drag coefficients earlier.
1965 Galaxie: .53 cd (stock) ~ 175 mph top speed (NASCAR version)
1969 Charger Daytona: .28 cd ~ 200 mph
Bugatti Veyron: .41 cd in normal mode / .36 cd in top speed mode ~ 253 mph
Aerodynamics are useful, but never underestimate the combination of courage and POWAAAAA. :P
#6, I read a story last night about a team rebodying a secondhand '66 Galaxie stock car as a '71 Torino in 1973 after the original body became too damaged (and too old) to use. So who knows?