That SINKing feeling

So installing a new sink and this happened






Shoulda double checked measurements but I was ensured that the sink was a standard length. Oh well, it's done now.

Any ideas or resolutions? Or do I just have to put the old sink back in?

*In case the photos don't work, the sink is 40mm too short and I have a gap in the counter.

Perhaps widen the hole a bit more and insert a nice piece of timber and make it an in counter knife block??
Nice sink BTW!