i have a vacuum leak from this part on the intercooler. i have ordered a new seal but also wonder if it could be the score on the arm itself, does anyone know what you would call the part and if i can get a replacment

If it were me, I would polish the affected wear area with grades of emery or sandpaper then the new seal will expand to fit the shaft - if it has gone too far then a new shaft or a sleeve (you used to be able to buy them for different diameter shafts