James,
It's less a question of angle than it is straightening and flattening the coarse ground factory bevels. As you're experiencing, this initial sharpening (grinding) will require some work on most traditional glue on heads the first time you sharpen them. After that initial "out of the pack" sharpening, touch-ups/resharpening will be much faster and easier.
If you use a file to get them started (which we highly recommend) use the file at a very low angle (just missing the ferrule) and concentrate on the laminated tip section. The main blade is much thinner and will come up quickly once the tip section is done.
The ink you're seeing in the center of the blades is telling you that the tip and heel of the blade are touching the stone correctly but the center is still being held above the stone. Take some metal off the tips (with a file) and you'll quickly see that ink in the center disappear. Don’t leave the coarse stone till the BHD is shaving, then refine with finer grits and finish by stropping on a piece of plain brown corrugated cardboard. Give me a call if you need some help. Thanks,
Ron
800 561-4339