The release button to allow the 35mm film winding nob locked up. This post hows how to get to the mechanism. I could not find anything on line that shows how it is done and hope it is useful.
I made a mistake of removing all the leatherette of the 35mm winding side. You will see it was difficult to remove. I hope I can glue them back together and not be too noticeable. To get to the mechanism, only about one third of the leatherette needs to be lifted. There are five screws holding down a plate that holds the wining mechanism. To get to three of the screws, part of the leatherette needs to be lifted. I made the mistake of trying to remove the whole leatherette. It would have made it a lot easier for me if I knew that. The red arrow points to the release button that had locked up. Pressing this button allows the film to be wind forward by one frame.
I also removed the 35mm winding nob in this photo. It was not required and it was tricky to put it back.
Although removing the whole side will give you access to one of the focus rack to remove the old grease, clean and put new grease on the focus cams. This what it looks like after I removed the old grease but before adding new grease onto the focus mechanism.
This is what the side panel looks like from behind once removed. The mechanism is a lot more simple than I was expecting.
Assembly is the reverse of disassembly. If you do not remove the 35mm winding nob, it is quite straight forward.
