This thing looks to be in decent shape -- especially for MA. I noticed the vents on the trunk -- I thought those were only a 1971 thing but I'm no expert https://www.facebook.com/marketplace/item/1146851759534417/
Listed as a '72. It has a 1972 front bumper and 1972 grille. Someone replaced the boot lid for a louvered '71 boot lid.
Here's another model year 1972 Riviera with a 1971 louvered boot lid, also for sale on Facebook Marketplace: 1972 tail lights and rear bumper, with the rubber strip: You can't see the grille, but the car has the 1972 front bumper, with the rubber strip: Click screenshot to view the listing on Facebook