The trades after fork are not the big problem i think, because many of the trades were old coins that already were on coinedup, so it isn't necessary to revert all trades.

The problem are the coins that were deposited to coinedup after the fork and then exchanged.
It should be possible to get the data from coinedup about the deposited amounts of etoken after fork. It shouldn't be that many deposits, because the most etok after fork were mined by a few solo miners.

Then we can collect donations for coinedup, to replace the exact amount of etoken deposited to coinedup after fork.
If it is too much, the exact amount of missing etoken could be included in the new fork and send to coinedup?
That way, the etok balances of the user accounts at coinedup would just remain the same since when the exchange went offline and nobody would lose anything.

(I don't know how coinedup deposits work, but i expect it to be a single wallet with different adresses for deposit? If thats true it should be possible like i explained.)