An update. The roofers were actually recovering the roof of our beach hut with rubber (and replacing facias,etc) so it wasn’t a big job but I had sold the job on to two of our neighbours so it was certainly worth their while making the 200 mile round trip!
The cost of the doors was £1000 and I fitted them myself, and the cost of replacing them would almost = the invoice for our roof work.
The beach hut is shared with my sister and she has quite rightly pointed out that, although very disappointing, no-one has died and the stain will be battered off by the weather in a few years. Part of me wants to replace the doors (especially if they have insurance) but another side thinks that maybe we should just let it go.
Due to the nature of the place, if we’re there the doors are open and you can’t see the stained side at all. Not sure if there may be an issue with one side of the doors having a coat of ‘something’ while the other is bare. If so that could be more serious.