I have cut and chamfered the bow ends of the first stringer and secured it in place. I tired sanding the chamfer, which works but is very slow as it is really quite long. I found that it is much quicker, and more accurate, to cut the bulk of the chamfer with a Japanese pull saw, and just finish it off by sanding. This makes rounding the surface much less likely.
This stringer is now glued and ring nailed from the centre frame to the bow frame. At the stem it is drilled right through and both stringers are held by a copper wire pushed through and clenched at each end, bound by strong twine through two positioning holes in the stem and then all bedded on Sikaflex. Bit messy but seems to work well. I need to repeat at the stern and then fit all the remaining full length stringers. The end chamfers will get more acute and much longer as I approach the keel.