An anonymous correspondent has a theory on your latest posting (largely based on someone telling him why they did it on their home fitted out boat).
The boat is so underweight that you need to place large heavy lumps of metal in the boat to bring it up to weight. But the weight of those bits of metal is limited, so you don’t call them correctors, you call them re-inforcing, at which point they become free !. Back in the days when correctors were carried at the extreme side of the boat (rather than in the middle), this had the advantage of getting the weight further inboard.
A.
The Flying Fifteen Blog 