In general, I am now able to get the deck on and off, and maintained pretty well. Thanks for all the advice. One thing I still find a little annoying are those little metal clips which hold the arms used to raise and lower the deck when not in use. That could have been better engineered.
I do have some trouble moving the deck around to work on it. I have seen a thing called a mower deck dolly, which looks like it might be useful. Now I lug the deck up onto a pallet and move it into the garage with forks. I won't be able to do that kind of lifting for too many more years.
I also found a technique which is helping a bit with excess grass clumping I was having. Previously I was trying to maximize the amount of grass I cut by using the majority of the deck to cut a swath of grass. But by cutting fresh grass with just a little over half of the deck, the mower is processing the cuttings better and leaving less clumps. I will continue to refine.