I just tried to make a superstructure of USS PORTLAND from Fly Model. Since the instructions are not ENGLISH, I couldn't understand the detail, but I think I managed to build one from diagrams. One thing: I found there are several 'w' marks. I could not find 'w' parts anywhere. What does 'w' means and where can I find it? The following picture shows some of 'w' marks I found. Thanks in advance.