Nice piece. I assume that it's red elm (also known as hard elm, slippery elm, etc.), not American or grey elm?
I'm working on a large piece in red elm and am also coloring it to bring out the grain. Did you use dye, pigment, or a commercial mix? What type of finish? Also, did you do any filling of the pores or simply left them au naturel?
As far as bookmatching the grain goes, I got around that problem by using shop veneer. My door panels (or anything else) are 1/8" elm on both sides of 1/2" baltic birch. Very stable and gives great control over the grain appearance.
Glad to see someone else working in elm, it's my favorite domestic wood.