Good news - after learning to use an angle grinder (fun!), how to pop rivet (ditto), and discovering the joys of Sikaflex (it's almost all gone off my skin now after two weeks), the repair job we did was good enough that the DVSA tester guy didn't even mention it, let alone say there was a problem! And we hadn't covered it up or anything, it was all right there to be seen.
Very happy with that result!
