Who knows what can happen to them when they just sit? They can crack. Odd that it has a cracked bridge from just a few games. Could have happened while it was sitting. Depends on in what kind of environment it was it AND the care with which the driller drilled it.
If I were you, I'd sand it down to about P500 grit, bring it up to 2000 or so and then check the reaction. If it doesn't react properly or even within a reasonable set of parameters, I'd put it aside. Might not be worth plugging and redrilling and doing an extraction. Core might even be cracked, though I doubt it. (very curious about that cracked bridge ...)
The sanded Trimax V2 came about 1200 grit dull. In that range it should still handle medium oil, maybe a bit more. You have plenty of hand to use it on medium(+) oil. Gamebreaker coverstock is stronger, of course. Might not need to be as dull as the Trimax. (V2 was roughly equivalent to Danger Zone's PK 18, which, when sanded, can easily handle today's medium oil.)
"None are so blind as those who will not see." "Some bowlers are crazy as pickled cats."
