This is yet another dual mode key i.e. a combined straight key and paddle, this will be the third one I have built and probably the last, I have learnt a lot building them if only my own limitations as a model engineer :()  the design criteria is, as far as I'm concerned,  the ease of changing from one mode to the other, and after changing ease of setting up again if required, and quality of the two modes, they are all of course a compromise as far as I can tell, a key dedicated to the job seems a better option i.e. owning two keys! but the novelty aspect and fun of building one and using it is great and for me that's what its all about, I have come to my own conclusion that the best option is to build a straight key all in one unit and then swivel the whole thing in paddle mode, having already tried the other options of gimbal and rotary action, I suppose in a way this is another gimbal type with the straight key bit as the top half, but very different to make, I'm hoping I've ironed out most of the bugs when I built key 074 which uses the same pivot system that I'm going to use in both parts of this key, as you can see above  the contacts and gap adjustment are in the isolated nose, it has a very nice lightweight action, and the swivel bearing base works very well, the mechanics in the nose were quite tricky as the two adjustments for straight key tension and paddle tension had to work from the same point but independently, but it all works well, I have left the straight key on as it were as it doesn't seem to affect paddle mode, paddle mode is stopped by simply tightening one of the paddle gap adjusters until the paddle is frozen, the part that seems most effective and yet simplicity is the dual purpose knob! it feels very good in both modes. It is a nice key and this Mk3 seems to be the best option for a dual mode key, Had enough of dual keys, bit to complex time for a simple straight key again I think :()