Looks to be a very clean fairly loaded car, 231 V6 Automatic, sport steering wheel, Power Steering & Brakes, A/C, dual Sport Mirrors, AM/FM Stereo, Long Center Console, adjustable drivers side seat back, Some sort of gauge package as I see a Tach (rare option on a V6 car). But the Base Vega style 10 Hole Rims, but with Trim rings & olds Logo dog dish's https://newyork.craigslist.org/fct/cto/d/new-milford-1975-oldsmobile-starfire/6964348061.html
I gotta say, that is a stupendously clean car for its age, and an excellent candidate for a concours rotisserie resto.
Tach was standard on everything except the "S"(tripper) model Starfire and Skyhawk. 1975 was much different than later model H-Specials with a raised transmission tunnel made to clear the proposed Wankle engine which never materialized. A few minor things wrong if was to be judged in concours (radiator cap, exhaust is wrong to name a few) but a very nice car to start with. I would hope someone will buy it and just maintain/improve as it is and not try to "improve" it with a V8. Notice the engine color. That is the correct color for 1975 Buick engines, a medium metallic blue/aqua. 1967 to 1974 was Buick Red and 1976 and later GM engines were pretty much all painted GM Corporate Blue.