I have discussed this a length with one of the proshop guys here.  We decided that using sandpaper would sand the urethane that is in the cover but won't sharpen the particles.  I use sandpaper on my Big B particles all the time without any problems.  However, once or twice a year I have them trizact to the grit I want them at.  

My suggestion would be to resurface it and tell your friend to just have the proshop trizact it to the grit he wants.  I would do it that way.

Andrew
--------------------
FUFU
"Act like you've been there before"

I once had a Pro Zone Azure sanded to 320!  It scared the hell out of me!!!
However it did not damage and worked great giving me a small amount of swing area on a shot no one else could play!  (1 board).

The thing about Brunswick's is that they respond so well to the Trizact.

I used to sand my Pro Zone Violet to 1000, quickly lightly and not often(3 times a year), then it would lose it's reaction.  I'd take it in to a distant proshop(PITA) and have him Trizact to micron 10.  Voila, like new.

Now on many particles I do scotch brite now and have seen no reduction in performance.  I often saw a decrease with sandpaper on other companies very fragile particles.

If time is of the essense scotch brite.  If perfection is desired, trizact.

Sand very judiciously all particles.

REgards,

Luckylefty