Hello, all new here, Thanks for having me. My interest is in finding Model # and P/N's of items for the correct model. So, the head casting is a DP-225, and is missing the pulley/belt guard. Would love to replace it. Are the various covers somewhat interchangeable, as far as 14", 17" models? It seems the mount holes line up, etc. Thank You and I look forward to learning more, Tim