Thinking about it overnight (as you do) I realise that if the keel/centreboard housing is ok, then the damage is probably due to the bilge keel supports on the trolley being higher than the keel support (derr!), so the issue is probably not hogging of the keel but deformation of the bilge keel area, this would make the hull a bit flabby and soft and you might even detect a slight hollow if you held a flexible batten of wood against the outside of the hull.
So supporting the boat at bows and stern, then applying some downward pressure above the damage, possibly by adding weight, perhaps in the form of sandbags, might get the hull shape back. Or maybe strutting down onto the damaged area so that you have room to work at the site of the problem.
I realise I am going off on one here (what does that mean?), as you have said you will be looking to get the repairs done professionally, but it does go to show that even quite serious damage can be fixed (in my mind at least…)
Good luck whichever way you decide to go.