Last year I experimented with adding a MB 550 pan to a #3 duke. I bought a dozen a couple of years ago they were on clearance for like 9 bucks a trap. I modded one last year and was happy with the results took a couple of coyotes with it. Fairly simple to do without having to disassemble the trap . 1 Remove Pan&dog 2 Remove the 2 tabs that the pan attached 2 I used a oscillating cut off tool. I just scored the side a little down flush to the frame and then wiggled it back and forth till it sheared off. 3 I removed the MB550 pan spring pin from that came with it, theirs have a wider offset. Then used a dremmel cutoff wheel to make a slot on each pan hinge. 4 install the new dog then open hinge loops up on the pan just enough to go over the spring pin and crimp back shut. Set the trap to check pan level. I consider these now to be my poor mans 650 Pro's. No more pan adjustments during winter it cost me 4 bucks a trap