My window sill is a rectangle, my window reveal is a trapezoid :-(

[Dudefinch]

I fkd up. I ordered oak window sills for our kitchen windows. One is ok, one is not. The length measurement I gave the supplier was for the edge near the front beading 1182mm. But just putting it up against the reveal now I see the back edge closest to the window is 1198mm, so there's a 7/8mm gap either side of the back edge. Obviously I didn't factor in that the builders hadn't made the reveal exactly square, I should have thought to measure the front and back edge. But I didn't. What would you advise I do? Is there a way this could be altered to still look OK in there or something else I should do? Or just buy another one with the right measurements? This one was £70.
Man, this was supposed to be a nice dopamine enriching job for a Sunday afternoon, nothing's ever easy!

 

[StephenStephen]

If you're confident to cut it, you could do so so that the edges are parallel with the walls either side, then put some white filler either side.

 

[foxhole]

Clear silicon or flooring caulk for a colour match .

 

[Dudefinch]

You think caulk is ok for a 7/8mm gap?