Finished shaving the rivets from the patch on the rear curbside end cap segment. Think it turned out pretty good for my first one.

I've been polishing areas, mostly to make the neighbors happier, but moreso because I want to clean the seams, identify any leaking rivets etc and get all them sealed before the weather turns. I am really surprised how much filform is on this, and wondering if F9 or G6 would be better than the F7 I'm using. Wondering what others have encountered.
This is what a lower panel by the door looked like after an hour of work with F7.

One other interesting thing on the polishing side, is that I'm running across these streaks around areas that dripped, gutters for the doors and windows, rivets on corners of window frames, etc. It is white at first, after further polishing it still shows, and is almost rainbow colored. Any ideas on how to remove this?

Finally, wondering if anyone has insight on these handles. On all 4 corners of the trailer, just above the window, screwed into the last bow front and back. Any ideas on what they are for? Very pitted, been there quite awhile obviously. Only think I could think is maybe they were for guide ropes when they were being lifted on and off ships at the various ports?!?