I have a friend that brought me a Partner K650 mark II stump grinder to work on. I got it fixed but cannot find the correct air filter. He brought a part number some shop gave him which is 505315571. The model on the machine is 2480405. I found some on amazon that say k650 but not mark II but active II & III. And they all say concrete saws. Do these take the same filter? Any help would be appreciated as he needs one asap. Ps. This is not the pre-cleaner that he needs, but the main paper pleated one.