We're selling soon and are therefore tidying up the place. The kitchen
is looking good except for the carcasses.

They're late 1980s/early 1990s board (not sure what the correct term is
(melamine faced chipboard?), but it's the sort that blows when water
gets in behind the facing material). Guess what? Steam has got in
above the hob where the facing strip on the bottom of the side board of
the carcass has peeled away a bit.

This has led to:

(a) A raised ridge of ~5mm along the full length of the unit
(b) A 10*3mm chip in that ridge

Does anyone know how to fix this? My current plan is to fill the chip
with woodfiller. Prime the filler and then, to get everything to blend
in, paint with International melamine kitchen cupboard paint.

I thought about sanding the ridge down level with the rest of the
carcass, but I can just see that going pear shaped. Am I wrong there?
I'd like to do a decent job, or at least as decent as you can without
replacing.

Thanks.