Suggestions please for restoring water marked and discoloured wooden kitchen cupboard doors

[reny]

As a last resort I will buy replacement doors for some wooden kitchen cupboards I have inherited. Before doing that I would like to see if I could renovate them myself.There must be someone out there who has tried this. Very grateful for any hints.

What about painting them? I had some hideous orange pine kitchen cupboards when I moved in but they were fairly new so didn't want to relpace them - I sanded them down lightly and painted them with a F&B eggshell. They still looked good after 7 years - we are in the process of replacing them now but I was quite sorry to see them go in the skip!