Timber whisperers.....talk to me.

[Ozi Sapling]

Ah, thanks Feline Del.
As suggested by Stickinthemud and Bassman before.
I’ve ended up going traditional. Nearly roughed out now.

[DC]

If you're trying to find the grain on a quarter sawn board can you not run a plane down it both directions. The plane will "dig in" if you're going against the grain and plane nicely if you're going with it. When you find the spot where it will cut cleanly both ways you're getting real close to following the grain. I've never used this method in bow making but I remember doing it in Industrial Arts in high school.

[Woodely]

So you are saying  you cant get the proper dimension with what you have.   This diagram may help.
 "I’ve ended up going traditional. Nearly roughed out now. "  Make sure you post a couple pics of your work. 

thx.