Posted by duncan webster on 07/01/2023 12:18:58:
Using a countersunk screw in shear is not ideal. It would be better with a close fitting dowel at the business end and the screw just behind. Then the dowel would take the shear and the screw would just hold it to the tongue. As you are not trying to make 2 out of one it can be a bit longer.
What I did in terms of fastener & fastener mounting centres was exactly emulating the original Greenwood setup, just slightly less (& wasted) blade overhang away from cutting tip.
A bit of a bodge but so is much on a smallish lathe (Boxford)