The passenger side panel is now fully riveted in place. I altered the way I applied the Sikaflex from when I put the drivers side on and it seems to have made much less of a mess. It's academic anyway as I've sort of decided to put in carbon fibre panels as cockpit "trim".
Next job is to fit the bonnet properly, start re-crimping the loom, replace the sump, and fit the coolant hoses. These jobs and many others really!