Bathroom Window Sill

Had a cistern replaced (by professional) and he actually cut out a piece of the window sill to fit the cistern. Now I have this ugly badly cut window sill (sash window). Have stripped for painting. Looking for ideas on covering/replacing the sill. If covering it has to come over the front and be able to 'shap' around the cistern and down in front of sill. Tiles, laminate (match cupboards)? No I didn't shoot him but almost. Cracked/broken tiles, sink over knees in toilet (couldn't see what was wrong with it), glue and gap filler not cleaned. On the positive side I am learning how to do all these jobs so all is not lost.

Can you post a pic of the area? It will help us visualise and make suitable suggestions. I'm sort of thinking about a false sill and a sill apron to go down the front of the wall - made from 12mm Fj pine and sprayed up . Without seeing the problem I could be way off track.

Hope this works.

I have looked for the Fj pine to see how it works but... Did you suggest that for a particular reason ie water area, flexible? I like your idea of a false sill. Finished painting the window and walls, now for broken tiles!