I'm envious, I used to have access to a brake like that a few years ago, then my friend retired and sold off all the shop equipment. I'm also going to be fabricating a set of seats, though I'm torn between aluminium and mild steel. I'm not a bit fan of stainless, and I'm sure if I were to build a set out of steel that they would last the rest of the car's life.
There is a file on the yahoo list with a 3D drawing of a Europa seat. I think its an S2, as I've used it to make a plywood "mock up" to see if I can actually fit in the car with a seat in place (luckily the answer is yes). Though I wonder how the 3D file compares to an actual seat. I took the 3D file and created a 2D cut sheet in AutoCAD, I can send you a the CAD file or a PDF if you want.
Rod