Similar to Kevin you can review my project photos and questions/comments.
Once you have the door openings correct and braced you can move the bulk of the cab around as needed to get it level. Starting with the floor/firewall get the front cab mount area repaired. Depending on the integrity of your door hinge post and rocker panel you may be able to cut away the inner and outer cowl panels to provide access without loosing your hinge post location. There are a lot of interacting pieces in the rocker panel, door hinge post, inner cowl, inner-to-outer cowl, and outer cowl panels. A lot of those interactions may not be obvious depending on how much of the material has disappeared over the years.
If you can post pictures it would help everyone here provide more specific information regarding your specific circumstances.
Been perusing the build threads mentioned above.
Will be bracing the cab this weekend. I will post some photos at that time to ensure the bracing is up to par. Might be trying to make the braces adjustable with threads/lock nuts at each end so I can then make any adjustments to bring the body into spec per the FAM. Note sure if this is a sound approach?
I need to replace not only the floor pan but the floor supports also. The cab is currently on the frame so I will raise it and rest it on a couple of 4x4s front and rear so the cab is not being supported by the very floor mounts I will be replacing as part of the floor supports. Again hopefully this makes sense.
Paul