1. Painting the Runners
Painted the back of the clear parts. I sprayed without masking, so quite a bit of paint splattered onto the front. Wiping it off was a real pain.
2. Surface Treatment
There were quite a few noticeable sink marks, so I tried sanding, which led to a sanding nightmare. And yet, I still noticed quite a few areas that I missed treating.
3. Test Assembly
The clear parts are fragile, so I assembled them very carefully, but I found cracks in several gate marks. It's difficult.

It's totally a Messer (finished) | pokio's Gunpla works