The first floor framing was a challenge to say the least!
We wanted to save as much of the existing home as we could, but as we opened it up, we realized that much of the framing was subpar, and there were several areas where rot had gotten to the wood members or the wood was just not in good shape from decades of hot/cold & wet/dry cycles. It was dirty from the intrusion through the bad sheathing, it was brittle from being heated and cooled so much, and it was an odd size that varied quite a bit even amongst itself.
In the end, we saved a lot less of the home than we had hoped to, and spent a lot more time saving the parts we did than we probably should have (certainly more than we budgeted for!). All the corners were out of plumb, and had to be taken apart and reattached. All the heights were off so much and we decided we were doing so much work that we might as well add a few inches to the ceiling height of the first floor. Kind of a bonus, but a lot of work!
We love older homes, and we love saving them as much as we can. But, some days we had a really tough time making choices of what to keep and when to recycle it.