Ernie, a couple of years ago I built two Weissenborn style guitars at the same time using the same wood (koa). I have both the MIMF and StewMac plans - like others using the former where there were differences. However, at that time there was an article in American Lutherie (the GAL magazine) showing a Weissenborn built with Martin style angled tone bars instead of the usual ladder style (which the author said he preferred). My customer and I decided to build one each way - he could take the one he liked the best and I would keep the other one. Here are shots of the two bracing patterns
Interestingly, everyone who has heard them both prefers the classic ladder braced one - the tone seems a little better defined (the angled braced one seems more complex sounding which is not necessarily what you want on a slide guitar)
There are several very good Weissenborn threads here if you do a search. Some random thoughts from my build - when I made my mold I used the inside cutouts for a bending mold for my Fox bender. You will have to think about how to hold the headpiece in your mold - mine worked but was not optimal. The standard headstock layout has string angles that hit tuner posts - you might want to change the layout to give better angle. The back of my headblocks were curved which made mounting the tuners difficult - figure that into your design. I used bone for the saddles instead of fretwire - that gives me a little more height adjustment. Mine fit a Beard case perfectly.
If you have any questions let me know. Here are the finished Koa twins
Also, here are a couple of threads from another forum during construction
http://www.harmonycentral.com/t5/Acoust ... p/30160459
http://www.harmonycentral.com/t5/Acoust ... p/30278257