As a general comment, I wish people would stop calling these last Curlys the "post-stroke years" and start calling them the Columbia "You-ain't-gettin'-another-dime" Years. We're all aware of Curly's limitations at the time, but it's the utter lack of production values - one or two sets, almost nothing outdoors, few sight gags, reused scripts, reused footage, increased reliance on dialogue - that brings these last Curlys down way more than his health. Curly only seems to be laboring in Three Loan Wolves and parts of Monkey Businessmen; in the rest he seems to give a decent performance with whatever he has left in the tank, including a few physical bits that a modern doctor would absolutely forbid!
As a youngster I never gave a second thought to a weakened Curly - they were all older and a little slower and I knew what my grandparents were like. And I still loved them. Years later when I knew of Curly's stroke then I started to notice the decreased quality of the shorts. But even more years later I can recognize the absolute lack of money being put into the productions to know that Curly's health was mostly a small part of the drop in quality. Even without failing health, the productions practically eliminate playing to Curly's strengths anyway. The maudlin part is that Curly's stroke had more of an effect on his dialogue timing than his physical timing - at exactly the same time as Columbia was relying more and more on dialogue and paying less and less (inflation-wise) on the physical and sight gags. One only needs to watch the pre-Columbia stuff to see that Curly's talent favored the physical (even though he was good with dialogue) whereas Shemp's strong suit was dialogue; Curly's inability to continue was almost a blessing for Columbia because the increased reliance of dialogue practically REQUIRED Shemp instead of Curly. In a way it's kind of cool that the Stooge dialogue that has become part of the American lexicon - "we all put the yeast in", "Maha", and "The sword of Damocles" comes from this period; they certainly made the best out of a horrible situation.
Here's hoping volume 6 provides Sony the opportunity to put commentary tracks on a few of the shorts to provide viewers with some context and history of the 24-year series.