I was going to build two jigs, one for the full length but still wider at the end than 3/8", and then a smaller 6-8" jig ( depending on length of fletching, probably best kept uniform where they glue on) for the final taper to the 3/8", have them both fixed to the board and do the shaft in two separate hits, then fine finish by hand, if I get some stuff cleared out the way in good time I'll have a play around nocking something up, I got a few full length 1/2" poplar I can use., I got a great little Stanley hand plane too if I get any square lengths, I'm also going to try hazel whichis plentiful locally, was told it makes a good arrow.
Ruddy Darter.