Maybe it's just the pic,,but the cocking rod in the bbl lump (OP's pic) looks to have a shorter extension than the one in the DH pic.
Plus the tip is squared off on the OP's where the DH pic shows a slight 1/2 radius rounding to the tip.
Picture angle perhaps. I don't have one here to measure.
Or maybe it's been shortened and reworked a bit and is causing the problem.