The jacknife sofa came off of the frame in two pieces, and was simply bolted on with four bolts per section:
The jackknife was all sewn by hand (I had the bruised fingers to prove it) and the dinette cushions were done by machine. I had plenty of help from the fur brothers, then the human one thought it was funny so got into the game...oy!
Here are the notions I used - the twist pins were good for holding the fabric into place while I stitched, then I left a few of them in place in areas with larger gathers of fabric.
And the final product:
I also covered the accent strip in the window toppers to match the new fabric. Now I just need to replace the cabover privacy curtain and the little side window curtains up there as well, since they are still in blue tones.