I did say "snugly". Fridge is exactly 50cm wide by my measure. I can't even slip a plastic ruler into the gap on either side, so the space is less than 50.5cm by my guess.

55cm is the next standard width up from 50cm, but I'd have to have the kitchen refitted to get one of those in.

Good news is that the support doesn't look as bad as I first thought, but not quite sure how to fix it.