I have some pictures of one of the "true splitsprings" made in the depths of time by WS Horvath (at least I think that's what it says) -- if anyone would like to post the images for me, PM me with your email address and I'll email the images to you (note: this one has a unique main blade also - interesting pattern).
I also have a true splitspring that was made by Ashton & Jackson (IIRC - will need to dig it back up and take a look) -- a large wharncliffe whittler with birdseye rivets, stag scales, and iron rattail bolsters. Unfortunately I have no pictures of it and no way to make any at the moment -- I just wanted to tease you with it right now.
Most of the true splitsprings have no liner between the two secondary blades. They are also darned rare. Even BRL said once that he'd only ever seen a small handful of them.
-- Dwight
I also have a true splitspring that was made by Ashton & Jackson (IIRC - will need to dig it back up and take a look) -- a large wharncliffe whittler with birdseye rivets, stag scales, and iron rattail bolsters. Unfortunately I have no pictures of it and no way to make any at the moment -- I just wanted to tease you with it right now.

Most of the true splitsprings have no liner between the two secondary blades. They are also darned rare. Even BRL said once that he'd only ever seen a small handful of them.
-- Dwight