All above makes perfect sense. However, this picture shows a center hole nicely rounded off...:I agree with you. The fact that the sheave center hole is not chamferred or rounded off means to me that the loop is NOT supposed to go through. It would be guaranteed premature chaffing...I looked thru my 2015 HK catalog on just that point - that's got to be at least a 100mm block? Catalog shows NO units that loop thru the base. Looking at the busted side plate, and the block on the other side, they have a chamfered edge across the bottom hole, but sheave center edge is squared off. I could not fing that profile anywhere in the catalog. Old stock??