Does a Passenger Right Front Door and fender of a 4 Door Sedan 1972 CUTLASS fit a 1970 four door sedan,

 

Yes they interchange

 

The 70 fender will fit but they don’t have the raised ridges that were added to 71-72 fenders. Since all the NOS fenders are the 71-72 style you might be able to sell the 70 fender to somebody that needs it and buy a NOS or nice 71-72 fender for less.