Hi Joris,
I missed this thread until now. I build an L-1, and other small body guitars, and would be willing to share some info and insights with you. I don't actually have plans I can send by computer, because I've just traced old guitars and measured insides and drawn up my own. There is already tons of info out there on the web, and it's easy enough to finds lots of photos of old guitars' bracing, as well as contemporary builders' bracing. Like Slack mentioned, the bracing on so many of these old guitars was very inconsistent, so you can really brace it however you want. If you want to do ladder bracing.. well, it's a simple layout and the plans you can buy aren't going to tell you much more than a photo and some common sense already does. I can understand being broke, and just wanting to jump into a project... so you're gonna have to be resourceful. Have you built any instruments? Do you have woodworking experience? Do you have tools, clamps, etc..? You can do it without much.. but you've got to start somewhere. If you're looking for some specifics on thicknesses and brace widths and such, feel free to PM me with specific questions and I can send you some numbers.
Cheers,
Devin