the junkyard parts must have been changed too by previous owners. Original parts wiper blades have their brand stamped on the rubber too. The only test is solid fitment of the wiper blade spine to the arm - it should sweep smoothly across the glass, watch the lower end of the wiper blade as it moves up, if it vibrates then the frame is loose. The spine has small levers which sometimes bind due to dirt/rust etc, 1 drop of singer oil is recommended to each joint lever if that happens.
the real performance test is only seen in long life, if the wiper chatters after use of 6 months or so then the rubbers are bad, genuine blades wipe smooth and quiet for at least 2 years.
before you use the wipers, its best to make sure your glass is clean, I personally do a 2 step cleaning, one with ammonia with water and a towel, ammonia will remove lots of dirt/protiens from bugs and oils too. After that I use a fine steel wool pad and some ammonia and water mix, this step cleans everything that is literally stuck/bonded to the glass. Clean with water and paper to finish.
if you think ammonia is too stinky for you then try cheap white vinegar, it also is a great cleaner.
The last bit is choice, you need to mix hot water with alcohol, wipe it clean with clean terry towels and admire having literally invisible glass. The wipers will wipe cleanly too.
