The impeller doesn't look bad, but the edges could be worn causing excess clearance. You can measure it with a std feeler gauge. Ideally .006-.010 clearance. From what I'm seeing, Seadoo calls for a max clearance of .040, and in my opinion, that's WAY to much. I just rebuilt the pump on my STX1100 and the clearance is at .006. Can't tell from the pictures if the wear ring is stainless or plastic. Since it is so old, you might consider rebuilding, or sending the pump off to Impro's for a rebuild, and let them install a new Solas impeller while they're in there. If you post what year and model I can look and see what impeller they list for yours.