I've done this multiple times with graph paper and a pencil. Seems to work fine. I anticipate this will be even better due to the crispness of the lines of the template. One of the big tricks is flattening the bottom of the stave on the belt sander. Get both billets flattened to the same degree. That way, you aren't trying to play "guess the angle of the cut." Also, it doesn't have to be perfectly seamless if you use a gap-filling glue like resorcinol. If it's still too wide a gap, I might boil the ends and leave them to harden and dry for a week. I've heard that works, too. I'll let you know after I test it out tomorrow!
John