Have 77 L2 with Trimpe cylinder bars and hard surface concave. Under difficult conditions, it is not doing a good job opening all soybean pods. Has anybody have any experience with line board concaves after market (Sunnybrook)? Does anybody know if Sunnybrook or any other manufacturer makes a cylinder for the L Gleaner? This is my only dissatisfaction with machine. Do I have to go to rotary to eliminate this problem?