Today I ended the building of the wingtip lenses, it did no go as easily as expected as the riveting of the nutplates is a bit ackward. Then the plexi needs to be countersunk.
I'm not that happy with the result but as I intedended to use Tinnerman washers this will be hidden. The use of those washers allows also for some play and so I could align the lenses a bit better.