It turns out that I do have a tear in my left rotator cuff but it is minor and I won't need surgery. I should get a call to start physio any day. And my knee is getting closer to normal every day.
One of our daughters came home for a few days and helped me level the deck. I measured down the same distance on each post and marked them, then one post at a time we jacked up the deck next to each post, cut the post off at the mark with a reciprocating saw, dug out the bricks and made a hole a couple of feet deep and filled it with gravel (crusher run), tamped the gravel, lowered the deck back to level and adjusted the top of the gravel to leave room for a deck block, then lifted the deck again, slid the deck block into place and dropped the deck so the post sits solidly in the block. The deck is now flat and level in both directions. I expect the gravel to settle a bit, giving the deck a bit of pitch for drainage.
The old stairs were attached by nailing the stringers to the 2x6 facer of the deck from underneath so that you stepped down from the deck to the top step. While working on levelling the deck I realized that a lot of the 2x4 decking is pretty far gone. It was too late to get it finished this year so the new plan is to strip the 2x4s off in the spring, check the condition of the framing and replace whatever I need to then. So I decided to attach the new stairs with concealed stringer hangers so that I can remove them as a unit if I have to do anything serious with the framing. The first thing I learned is that with the hangers as low as possible the top step would be about 1.5" below the deck (= tripping hazard). The regular solution would have been to add another 2x6 below the facer and hang them from that so the step would be the same but the deck & stairs already block the light from the basement window and I didn't want to make that worse so that was out.
No prob - I'll just hang them so the top step is level with the deck and you walk out onto it before stepping down. Bit I had already hung the stringers temporarily with a couple of screws when I realized that I would need 6 steps instead of 5 to bring them down to the same grade as before and I couldn't take the stringers back with screw holes so I started exploring options. I could get another 2x6 and build a plinth/bottom step for them to sit on top of but I had no way to bring a 2x6 home and besides, it would look cobbled together. I was already planning to salvage a couple of patio slabs from the former dog pen (on the right in the pics - we aren't planning to have dogs again and one day we'll plant vegetables there so the slabs are redundant) for the stairs to rest on so they won't rot and I got a lot more gravel so why not raise the slabs to meet the stairs? But Then I would need to get more wood to build a frame around the slabs... My neighbour suggested I salvage some of the wood from the old stairs to build a frame around the slabs... OK but then I discovered that you are required to have a flat area at the bottom of the stairs and 2 slabs wouldn't be enough....
Here's what I ended up doing: The landing at the bottom of the stairs is 3x3 slabs (x 18" slabs = approx. 54' square), framed with PT wood from the old stairs and filled inside with gravel so the slabs are just a bit higher than the wood and I filled the gaps with sand mix concrete to deter weeds. I then backfilled around the outside of the frame with more gravel and spread the dirt from the holes under the posts plus some that my neighbour wanted to get rid of over it so that the grass will grow up to the wood and hold everything in place as the wood rots away. You can't see it very well in the pic but I set a couple of the slabs into the dirt/gravel to provide a clean place to stand while putting stuff into the composter (the big black thing to the right of the stairs) too.