Doing some research for a video I'll also post here and saw that the 2Seemy developer is closing up. You might want to make that order if you have been thinking about it. He said he has only a few Tascam cards left.
It looks like they use pretty standard PCB techniques, but maybe they're willing to share their blueprints, technical drawings and items listings.. It's a bit hidden on their site but if you do a search for 'gmail' under the FAQ page you'll find their email address.