Gary,
I got nearly done (not upholstry-that's the last step) and went back to 22" for the new section of the seating. After I put the cushions in place on the back, the new seat was too narrow for comfort. Luckily, the cushion I had cut down to 20" can be cut down further for my last back cushion!
I got pedestal for my new table, with a short 12" pedestal for converting to a bed.
I really wanted to put bins under the new seat, but got over-ruled...the dog's bed gets to go there! Fortunately, he is a small dog.
Anyway, thanks again for the great ideas.