Hi Brendan
I'd been misled on two fronts. Firstly, I had ISSEI for the Japanese immigrants, which I got from Google. Interestingly, my friend in Sheffield, with whom I share the crossword on Sunday morning, had the same. Once I had the N at the start of 19d it was a doddle.
Secondly, someone on this thread said it was the first five words of 25ac that provided the first letters for the anagram, but actually it was the third to eighth words. So my first instinct was right for 25ac, though I still don't get the definition. I no longer care.
I'm off to bake a cake for Bridge tomorrow. My bridge group is coming here. My husband doesn't approve. They've all had the double jab, so fingers crossed.