First off, lets get something worked out. Unless there was a release I don't remember or know about, the ONLY Columbia Black Knight was a Black PLASTIC ball. It was in the white dot line, with a cover just slightly harder than a regular white dot, but softer than a blue dot. The reason it doesn't hook like the urethanes of today is that it ISN'T URETHANE.
The urethane ball in this line was the Blue Knight, and it was a dull sanded blue color. You can check, but I am 99.99999999999999999999999999999999% sure of these facts.
The Black Knight does have a pancake core, but that's about the only thing you have right about it.
Now, the blue pearl Hammer IS a urethane ball. As was stated earlier, the large majority of these were pin-in balls, as pin-outs were thought to be of poor quality back then. Pin-outs do exist, but they are very rare and extremely hard to come by.
It probably won't hook as much as the modern urethanes, but it will be stronger that the Black Knight on DRY CONDITIONS.
As far as shooting spares with it, todays conditions are much heavier conditions than those we had back when the pearl Hammers were popular, and it would probably not be too noticeable that it was different than the ball you have now, because, even though the Hammer IS urethane, it just isn't capable of handling the amount of conditioner out there today. You get it on what is today considered truley dry conditions and it is a really good ball. I used one as my main strike ball for two years, back in the day.
In the end, the Blue Pearl Hammer is another great Hammer, just dressed in shiny, fancy clothes.
