Don, here some pics of a cushion that came with my project and was marked 'Lambda'. It puzzles me that there is no wooden frame, so I wonder whether it is correct. (maybe the seller of my car just wrote 'lambda' on it to make sure I would take the thing along
) If you want it, it's yours...
Now I know that Iain Simpson in Oz had the correct springs made for his car, and I believe he has another complete set, so I dropped him a mail, maybe he made some pictures to. I remember him pointing out that seat springs are different then the backrest springs.