It looks like some of the spacers have been possibly replaced which is probably why the pommels and brass nuts look a bit marred, although I would bet these are no newer than mid 20th century .
Maybe the leather dried out at some point .
Chris, it would be nice if the value of these hunters was worth having a pro restore them; but here in the US I think professional restoration would be more a labor of love .
I like the patina they have; it would be a shame to remove that .
The example I posted was a trade incentive item from a shirt company .
As an observation; I think we are treading more on a modern blade forum's territory here .
