m371961

Going where I've never been before. Starting work on top frame, have a few questions.
1. In the attached pic, I have to replace a section of metal. Am I correct to assume the metal has a angled slot that goes all the way to the end of the shown piece? (sorry for bad pic)
2. I have seen companies that have bolt/bushing kits. Anyone have any reccomended ones to deal with?
3. This may be a dumb question, but is it ok to operate the frame without canvas in place?
4. Some frame joints are riveted. Any suggestions for lubing these? (frame will be epoxy coat and painted)
Thanks, Pat