The only way I could make the left side panel of the upholstery kit work with the standard trim lever and flap setup was to cut out a rectangular section from the top fwd corner. No other way unfortunately, so that's what I did. After completing that and gluing all the fabric to the panel again I installed it all and had a look. Looks good. I still need to flue the Velcro strips on the cross tie and spar tunnel but I'll do that tomorrow.
Off course I went and sat down in my airplane to test how comfortable the seats are now, very comfortable indeed.