This is a bit of a fun key :) I saw a picture of a French Aircraft key called a Saram key, what interested me was its construction, mainly the adjusters which were tapered bars running across the top of the key arm, one acting as a gap adjuster as the tapered part was screwed in, and the other which lifted a flap which was connected to a spring to provide the variable tension, in the original design the key body seemed to be a sort of frame and pivoted at one end which I suspect would be a pretty heavy action, I thought I might improve on that by using a tried and tested standard straight key line-up with end contacts and a close in hard spring, It is proving quite difficult to make owing to my limited metal working skills and tooling but great fun, it works very well although its not an easy key to set up in as much as the tension range is quite limited and the gap adjuster is critical, shown with and without its brass cover and different knobs.