Home DIY

It looks to me as if our floorboards have had some rather hideous orangey stain/treatment at some point. Presumably this will sand off?

It will. It looks like its failing so it should come off fairly easily, but there is a risk that it will gum up the sanding paper. If so you can strip it with paint stripper and a scraper. Horrible job though.

The floorboards look a bit ropey to me compared to some of the examples I can find but I assume it's still reasonable wood, can anyone see any reason not to sand them back?

Plan to re-fill the gaps when you finish them.