A possible way to get parts (and engines) real cheap...
Since you are in Tulsa, check with your local Public Works Department. In my city, they regularly auction off used chain saws, weed eaters, blowers and other lawn care items for pennies on the dollar. An aquaintance of mine did this and got three big displacement Sachs Dolmar chain saws for about $15.00 total, and they are all in excellent running order. Hope this is a lead to follow up on.