Just to clarify, in case anyone is bewildered, it's only the digital step that's off topic for APUG.

Taking two 5x7" images, contact printing or enlarging them in the darkroom, lining the prints up on a light table and slicing through them at the seam with an X-acto knife and a straightedge, and mounting them together as a continuous image is perfectly on topic, and could fit in the LF or the Panoramic forum on APUG.