If its a real nice peice of wood you could make it work.Just splice in a 6" peice between two of the 29". That gives you 64". Then place the splice on the back of the riser then to finish up put an overlay of black glass and riser wood over the splice. If you make a nice joint it will hardly show on the side of the riser. The 29" will be plenty long for the belly veneers. Make sense? Bob