Today’s Saturday Stumper

Today’s Newsday Saturday Stumper, by Greg Johnson, offers a good challenge. In other words, a challenge that can be met. There are moments of odd trivia, such as 34-Across, ten letters, “Iceland, originally.” Or 55-Down, four letters, “Salutation popularized by ‘A Farewell to Arms.’” And moments of odd opacity, such as 3-Down, four letters, “Organic digger.” Or 48-Down, four letters, “The ‘where.’” (What?)

My favorite clues from this puzzle: 29-Across, eight letters, “What strollers carry with them.” 40-Across, four letters, “She’s seen in middle names.” And 41-Across, ten letters, “Cooler in the summer.” Especially 41-Across.

No spoilers: the answers are in the comments.