Michael,
Below a pic of more or less the same situation - back rests only test fit - during the carpeting of my 'red 66 about a year ago now. Just to illustrate that I can imagine how your fingers, your back and knees felt after these 5 hours. I like your two-tone more and more ...
Remember not to glue the leather on the sidepanels to close to the B-pillar side. There is that little screw (1/8") that needs to be turned in to keep the side panel in correct position.
Otto