I've just posted an article to my website on Hall ignition conversion for V4s. This article has been published before in the magazine of the Saab Enthusiasts' Club; now you have the advantage of being able to zoom in on the photos! Link: http://www.saabv4.com/index.php/project/hall-ignition/ You can download the article and print it to use it in the workshop if you want, this is how the whole site is intended to work.
There is always room for improvement, so if you have comments or questions let me know. Also please post your own Hall conversions here!
Nice stuff, Melle, you paint it in a way that it is difficult to say it doesn't worth the effort. I'll go for it, it's so easy to leave the key on and burn the pertronix that your option is simple perfect. (once it's fitted) Drill the dizzy shaft seems to be a delicate task.
Drilling is OK as long as you decently support the shaft, ideally by using a jig as described. File the top of the shaft flat/ roughen it a bit and punch a centre hole before drilling and you should be alright. Keep us posted on your conversion!