Nothing at all to laugh at, DSC. Looking good. Looking at the pictures of your doors, I can't tell what kind of material they're made of. It looks like an applied vinyl oak-grain material, with exposed MDF edges - is that right? I have a couple of things to recommend to you to that'll clean up, polish, and probably go a long way to covering the scratches and such. I'm hesitant to make those recommendations because I don't know what those door edges are.
If I may, I'd like to caution you not to go for flannel for upholstery. I may get some argument on this, but I think you'll be much more satisfied with an upholstery fabric with a flannel look, if the flannel look is really what you're going after. While flannel might be a little cheaper than a similar looking upholstery fabric, it won't wear nearly as well. I don't know what kind of camping you normally do, how dirty or wet people get, or if you have kids who seem to make spilling things a separate hobby on its own (like my kids did,) but most flannel isn't up to that kind of wear. It could be done - don't get me wrong. I think, however, that you'd be replacing the upholstery within 5 years - if that long. It would work for curtains and such, but I really think you'll be sorely disappointed if you had your seat cushions upholstered in it.