This is key No127 really it should have been put on the website after the other Amplidan copies but until recently it was just a collection of odd bits in a box left over from previous Amp projects, but I have mounted the pieces onto another base, this time using Acrylic instead of Delrin which is more like the original Amp, the step doesn't come out well in the picture as it is so shiny,  I have gone back to the original pin pivot idea of the original Amp on this one, lengthened the contact spring a little, and shortened the "Comforter" knob slightly, otherwise it is typical Amp, further down you can see this Mk4 next to my original Amp, and the Action before plating, lengthening the spring contact has given the key a more lightweight feel to it and being  lower slung it's more of a Greyhound than the original but still a typical long lever key.
very pleasant to use, great fun, I still have one steel plate left so there is a possibility of one more Amp copy, but I think that will be the last one.