Carb overflow tube on the spring is best. It's black so it blends in. A small piece of black pipe like plumbing pipe over the frame where the spring sits also helps stop the spring wearing away the paint on the frame. It's finding the correct size which can be difficult. Maybe overflow pipe with a split in it would be fine if it's too small.
Doesn't look right to me, the pivot arm is not positioned right, it should be a lot more upright, you may find the threaded part at the rear is way too far through the brake lever arm. You may also find having it that low means the spring is hardly tensioned so it doesn't return the setup as strongly as it should.
Check the brake lever for punch marks, the mark lines up with a similar one on the pivot arm.
Ted is correct is saying the split pin should be visible but the brake rod is fitted upside down, the part with the ridge for the pin to locate into goes on the inside as Phil says.
