Ya know, it has good bones. Reminds me of the house I grew up in. It would be a mountain of work but it could be really, really cute. I'd have to agree with not doing any work on it at all until you OWN it though. Doesn't sound like your in-laws can be trusted. You can go ahead and clean it up if you want but no way should you invest any money in paint or anything else for that matter.