In the remaining time today, I made a start on riveting the rollbar. I'm doing this in-situ to maximise the chance that there will be no problem aligning the rollbar with its supporting brackets. I reclecoed all of the bits, bolted the Bulkhead Brackets to their bases, and slotted the clecoed structure in place - no problem. I'll do as much riveting as I can while the assembly is in its final place. This should help it to "set".
The flush rivets don't go in easily and I'm not sure why. I ended up having to "touch drill" holes to get the rivets in. Too many to do for this to get finished tonight. And I have already done 9 hours so time to quit and have a drink while this is still fun ;-)