Due to a wrong drawing in the construction manual, we did countersunk the holes of the main gear angles in the wrong direction. On the photos you can see the rivets sticking out into the gear box.

rivets installed in the wrong direction

Later, we were informed the countersunk rivet-heads should be on the inside of the gearbox. Due to the countersinking, the inner side of the gear mounting box should be flat to pick up the landing-gear.