QUOTE(squirrel @ Feb 6 2008, 09:42 AM)

This may be a naive question, but is it common practice to have a coin re-graded to improve its perceived value, such as with this Dassier Ruble?
Yes, it goes on all the time (especially in the US coin market) because if the number on the slab goes up by even one point, then the coin is magically worth more (sometimes a LOT more).
QUOTE(squirrel @ Feb 6 2008, 09:42 AM)

Is this only possible by cracking the old slab, and sending the coin to DIFFERENT grader, and hoping for higher grade?
No, it can be resubmitted many times over to the same grading company (or a different one) until the higher grade is finally achieved.
I don't think it bothers the grading companies to have the repeat business.
QUOTE(squirrel @ Feb 6 2008, 09:42 AM)

What would happen if the coin came back lower...
Then it would magically be worth less than it was earlier because the number on the slab would be lower.
QUOTE(squirrel @ Feb 6 2008, 09:42 AM)

can you crack it open AGAIN and send it back to the first slabber, and get it re-slabbed at the old grade, since it was a recorded coin?
I doubt it, although I believe the grading company would be happy to collect the fee again.